compat_ioctl: hook up compat handler for FIEMAP ioctl

The FIEMAP_IOC_FIEMAP mapping ioctl was missing a 32-bit compat handler,
which means that 32-bit suerspace on 64-bit kernels cannot use this ioctl
command.

The structure is nicely aligned, padded, and sized, so it is just this
simple.

Tested w/ 32-bit ioctl tester (from Josef) on a 64-bit kernel on ext4.

Signed-off-by: Eric Sandeen <[e-mail]>
Cc: <[e-mail]>
Cc: Mark Lord <[e-mail]>
Cc: Arnd Bergmann <[e-mail]>
Cc: Josef Bacik <[e-mail]>
Cc: Jan Kara <[e-mail]>
Cc: <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>
Signed-off-by: Linus Torvalds <[e-mail]>

fs/compat_ioctl.c

···
 COMPATIBLE_IOCTL(FIOASYNC)
 COMPATIBLE_IOCTL(FIONBIO)
 COMPATIBLE_IOCTL(FIONREAD)  /* This is also TIOCINQ */
+COMPATIBLE_IOCTL(FS_IOC_FIEMAP)
 /* 0x00 */
 COMPATIBLE_IOCTL(FIBMAP)
 COMPATIBLE_IOCTL(FIGETBSZ)