cifs: Fix incorrect return code being printed in cFYI messages

FreeXid() along with freeing Xid does add a cifsFYI debug message that
prints rc (return code) as well. In some code paths where we set/return
error code after calling FreeXid(), incorrect error code is being
printed when cifsFYI is enabled.

This could be misleading in few cases. For eg.
In cifs_open() if cifs_fill_filedata() returns a valid pointer to
cifsFileInfo, FreeXid() prints rc=-13 whereas 0 is actually being
returned. Fix this by setting rc before calling FreeXid().

Basically convert

FreeXid(xid);			rc = -ERR;
return -ERR;		=>	FreeXid(xid);
				return rc;

[Note that Christoph would like to replace the GetXid/FreeXid
calls, which are primarily used for debugging.  This seems
like a good longer term goal, but although there is an
alternative tracing facility, there are no examples yet
available that I know of that we can use (yet) to
convert this cifs function entry/exit logging, and for
creating an identifier that we can use to correlate
all dmesg log entries for a particular vfs operation
(ie identify all log entries for a particular vfs
request to cifs: e.g. a particular close or read or write
or byte range lock call ... and just using the thread id
is harder).  Eventually when a replacement
for this is available (e.g. when NFS switches over and various
samples to look at in other file systems) we can remove the
GetXid/FreeXid macro but in the meantime multiple people
use this run time configurable logging all the time
for debugging, and Suresh's patch fixes a problem
which made it harder to notice some low
memory problems in the log so it is worthwhile
to fix this problem until a better logging
approach is able to be used]

Acked-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Suresh Jayaraman <sjayaraman@suse.de>
Signed-off-by: Steve French <sfrench@us.ibm.com>

fs/cifs/file.c

@@ -300,14 +300,16 @@ int cifs_open(struct inode *inode, struct file *file)
 	pCifsInode = CIFS_I(file->f_path.dentry->d_inode);
 	pCifsFile = cifs_fill_filedata(file);
 	if (pCifsFile) {
+		rc = 0;
 		FreeXid(xid);
-		return 0;
+		return rc;
 	}
 
 	full_path = build_path_from_dentry(file->f_path.dentry);
 	if (full_path == NULL) {
+		rc = -ENOMEM;
 		FreeXid(xid);
-		return -ENOMEM;
+		return rc;
 	}
 
 	cFYI(1, ("inode = 0x%p file flags are 0x%x for %s",
@@ -494,8 +496,9 @@ static int cifs_reopen_file(struct file *file, bool can_flush)
 	mutex_unlock(&pCifsFile->fh_mutex);
 	if (!pCifsFile->invalidHandle) {
 		mutex_lock(&pCifsFile->fh_mutex);
+		rc = 0;
 		FreeXid(xid);
-		return 0;
+		return rc;
 	}
 
 	if (file->f_path.dentry == NULL) {
@@ -845,8 +848,9 @@ int cifs_lock(struct file *file, int cmd, struct file_lock *pfLock)
 	tcon = cifs_sb->tcon;
 
 	if (file->private_data == NULL) {
+		rc = -EBADF;
 		FreeXid(xid);
-		return -EBADF;
+		return rc;
 	}
 	netfid = ((struct cifsFileInfo *)file->private_data)->netfid;
 
@@ -1805,8 +1809,9 @@ ssize_t cifs_user_read(struct file *file, char __user *read_data,
 	pTcon = cifs_sb->tcon;
 
 	if (file->private_data == NULL) {
+		rc = -EBADF;
 		FreeXid(xid);
-		return -EBADF;
+		return rc;
 	}
 	open_file = (struct cifsFileInfo *)file->private_data;
 
@@ -1885,8 +1890,9 @@ static ssize_t cifs_read(struct file *file, char *read_data, size_t read_size,
 	pTcon = cifs_sb->tcon;
 
 	if (file->private_data == NULL) {
+		rc = -EBADF;
 		FreeXid(xid);
-		return -EBADF;
+		return rc;
 	}
 	open_file = (struct cifsFileInfo *)file->private_data;
 
@@ -2019,8 +2025,9 @@ static int cifs_readpages(struct file *file, struct address_space *mapping,
 
 	xid = GetXid();
 	if (file->private_data == NULL) {
+		rc = -EBADF;
 		FreeXid(xid);
-		return -EBADF;
+		return rc;
 	}
 	open_file = (struct cifsFileInfo *)file->private_data;
 	cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
@@ -2185,8 +2192,9 @@ static int cifs_readpage(struct file *file, struct page *page)
 	xid = GetXid();
 
 	if (file->private_data == NULL) {
+		rc = -EBADF;
 		FreeXid(xid);
-		return -EBADF;
+		return rc;
 	}
 
 	cFYI(1, ("readpage %p at offset %d 0x%x\n",