[GFS2] Remove (extra) fs_subsys declaration

This is already in Linus' tree, so we don't need to add
another one.
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

include/linux/fs.h

@@ -1377,9 +1377,6 @@ extern struct subsystem fs_subsys;
 #define FLOCK_VERIFY_READ  1
 #define FLOCK_VERIFY_WRITE 2
 
-/* /sys/fs */
-extern struct subsystem fs_subsys;
-
 extern int locks_mandatory_locked(struct inode *);
 extern int locks_mandatory_area(int, struct inode *, struct file *, loff_t, size_t);