coredump: make __get_dumpable/get_dumpable inline, kill fs/coredump.h

1. Remove fs/coredump.h. It is not clear why do we need it,
   it only declares __get_dumpable(), signal.c includes it
   for no reason.

2. Now that get_dumpable() and __get_dumpable() are really
   trivial make them inline in linux/sched.h.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: Alex Kelly <alex.page.kelly@gmail.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Petr Matousek <pmatouse@redhat.com>
Cc: Vasily Kulikov <segoon@openwall.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs/exec.c

@@ -62,7 +62,6 @@
 
 #include <trace/events/task.h>
 #include "internal.h"
-#include "coredump.h"
 
 #include <trace/events/sched.h>
 
@@ -1609,7 +1608,6 @@ void set_binfmt(struct linux_binfmt *new)
 	if (new)
 		__module_get(new->module);
 }
-
 EXPORT_SYMBOL(set_binfmt);
 
 /*
@@ -1628,22 +1626,6 @@ void set_dumpable(struct mm_struct *mm, int value)
 	} while (cmpxchg(&mm->flags, old, new) != old);
 }
 
-int __get_dumpable(unsigned long mm_flags)
-{
-	return mm_flags & MMF_DUMPABLE_MASK;
-}
-
-/*
- * This returns the actual value of the suid_dumpable flag. For things
- * that are using this for checking for privilege transitions, it must
- * test against SUID_DUMP_USER rather than treating it as a boolean
- * value.
- */
-int get_dumpable(struct mm_struct *mm)
-{
-	return __get_dumpable(mm->flags);
-}
-
 SYSCALL_DEFINE3(execve,
 		const char __user *, filename,
 		const char __user *const __user *, argv,