btrfs/219: add to the auto group

Add this test case back to the auto group which reverts the
commit e2e7b549380a ("fstests: btrfs/219: remove it from auto group") since
the previously missing kernel commit 5f58d783fd78 ("btrfs: free device in
btrfs_close_devices for a single device filesystem") has already been
integrated.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Zorro Lang <zlang@kernel.org>

tests/btrfs/219

diff --git a/tests/btrfs/219 b/tests/btrfs/219
index 0bbfd69..9da835d 100755
--- a/tests/btrfs/219
+++ b/tests/btrfs/219
@@ -12,7 +12,7 @@
 #
 
 . ./common/preamble
-_begin_fstest quick volume
+_begin_fstest auto quick volume
 
 # Override the default cleanup function.
 _cleanup()