SRPT: Fix odd use of WARN_ON()

While WARN_ON("const string") will work, it's intent is not obvious.
The warning is more useful by showing the "state" value.

Signed-off-by: Grant Grundler <grundler@chromium.org>
Signed-off-by: Roland Dreier <roland@purestorage.com>

drivers/infiniband/ulp/srpt/ib_srpt.c

@@ -1374,7 +1374,7 @@ static int srpt_abort_cmd(struct srpt_send_ioctx *ioctx)
 		target_put_sess_cmd(ioctx->ch->sess, &ioctx->cmd);
 		break;
 	default:
-		WARN_ON("ERROR: unexpected command state");
+		WARN(1, "Unexpected command state (%d)", state);
 		break;
 	}