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/ext4/ioctl.c

@@ -1360,6 +1360,7 @@ long ext4_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 	}
 	case EXT4_IOC_MOVE_EXT:
 	case EXT4_IOC_RESIZE_FS:
+	case FITRIM:
 	case EXT4_IOC_PRECACHE_EXTENTS:
 	case EXT4_IOC_SET_ENCRYPTION_POLICY:
 	case EXT4_IOC_GET_ENCRYPTION_PWSALT: