[XTENSA] Fix fadvise64_64

Xtensa passes long long arguments in a even/odd register pair,
so we also need to shuffle the arguments when passed through the
system call to avoid an empty argument register.

Signed-off-by: Chris Zankel <chris@zankel.net>

arch/xtensa/kernel/syscall.c

@@ -93,3 +93,8 @@ asmlinkage long xtensa_shmat(int shmid, char __user *shmaddr, int shmflg)
 	return (long)ret;
 }
 
+asmlinkage long xtensa_fadvise64_64(int fd, int advice, unsigned long long offset, unsigned long long len)
+{
+	return sys_fadvise64_64(fd, offset, len, advice);
+}
+