fs: compat_ioctl: move FITRIM emulation into file systems

Remove the special case for FITRIM, and make file systems
handle that like all other ioctl commands with their own
handlers.

Cc: linux-ext4@vger.kernel.org
Cc: linux-f2fs-devel@lists.sourceforge.net
Cc: Mikulas Patocka <mikulas@artax.karlin.mff.cuni.cz>
Cc: linux-nilfs@vger.kernel.org
Cc: ocfs2-devel@oss.oracle.com
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

fs/hpfs/dir.c

@@ -325,4 +325,5 @@ const struct file_operations hpfs_dir_ops =
 	.release	= hpfs_dir_release,
 	.fsync		= hpfs_file_fsync,
 	.unlocked_ioctl	= hpfs_ioctl,
+	.compat_ioctl	= compat_ptr_ioctl,
 };