test/rsrc_tags: turn assert into actual error logging
test/rsrc_tags: turn assert into actual error logging

It's hard to debug a failure when you just get an assert, since we
don't know what the errors were or which sub-test failed. Turn a
noticed error into something legible so we get decent output.

Signed-off-by: Jens Axboe <cd8c6775e60d6f67a6984377324e5290df3d5358@kernel.dk>

axboe/liburing,axboe/liburing,axboe/liburing