Documentation/filesystems: remove out of date reference to BKL being held

Documentation/filesystems/vfs.txt incorrectly states that the kernel is
locked during the call to statfs (Documentation/filesystems/Locking
correctly says it is not). This patch removes the offending sentence.

remove reference to BKL being held in statfs

Signed-off-by: Adrian McMenamin <adrian@mcmen.demon.co.uk>
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Documentation/filesystems/vfs.txt

@@ -277,8 +277,7 @@ or bottom half).
   unfreeze_fs: called when VFS is unlocking a filesystem and making it writable
   	again.
 
-  statfs: called when the VFS needs to get filesystem statistics. This
-	is called with the kernel lock held
+  statfs: called when the VFS needs to get filesystem statistics.
 
   remount_fs: called when the filesystem is remounted. This is called
 	with the kernel lock held