Fix FREEZE/THAW compat_ioctl regression

Commit 8e961870bb removed the FREEZE/THAW
handling in xfs_compat_ioctl but never added any compat handler back, so
now any freeze/thaw request from a 32-bit binary ond 64-bit userspace
will fail.

As these ioctls are 32/64-bit compatible two simple COMPATIBLE_IOCTL
entries in fs/compat_ioctl.c will do the job.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs/compat_ioctl.c

@@ -1913,6 +1913,9 @@ COMPATIBLE_IOCTL(FIONREAD)  /* This is also TIOCINQ */
 /* 0x00 */
 COMPATIBLE_IOCTL(FIBMAP)
 COMPATIBLE_IOCTL(FIGETBSZ)
+/* 'X' - originally XFS but some now in the VFS */
+COMPATIBLE_IOCTL(FIFREEZE)
+COMPATIBLE_IOCTL(FITHAW)
 /* RAID */
 COMPATIBLE_IOCTL(RAID_VERSION)
 COMPATIBLE_IOCTL(GET_ARRAY_INFO)