xfstests 073: unmount source image in cleanup

Test 073 is currently failing w/ xfs_repair problems, and when
it does, the whole series stops because the test dir still has
a loopback mounted filesystem on it, and it can't unmount.

Fix that.

Signed-off-by: Eric Sandeen <sandeen@sandeen.net>
Reviewed-by: Christoph Hellwig <hch@lst.de>

073

@@ -44,6 +44,7 @@ _cleanup()
 	umount $SCRATCH_MNT 2>/dev/null
 	umount -d $imgs.loop 2>/dev/null
 	[ -d $imgs.loop ] && rmdir $imgs.loop
+	umount -d $imgs.source_dir 2>/dev/null
 	[ -d $imgs.source_dir ] && rm -rf $imgs.source_dir
 	rm -f $imgs.* $tmp.* /var/tmp/xfs_copy.log.*
 }