Revert "lshal: do not pthread_kill"

This reverts commit f2daedf53d98c013d80776e05694f13a4127984f.

Reason for revert: breaks wear devices

Bug: 315194872
Change-Id: I879da9c77a9bd1275e45b316fe88ec91d498ec0b
diff --git a/cmds/lshal/Timeout.h b/cmds/lshal/Timeout.h
index 012a5d5..e8d22d9 100644
--- a/cmds/lshal/Timeout.h
+++ b/cmds/lshal/Timeout.h
@@ -72,14 +72,10 @@
         return false;
     }
     bool success = state.wait(now + delay);
-    if (success) {
-        pthread_join(thread, nullptr);
-    } else {
-        // b/311143089: Abandon this background thread. Resources for a detached
-        // thread are cleaned up when it is terminated. If the background thread
-        // is stalled, it will be terminated when returning from main().
-        pthread_detach(thread);
+    if (!success) {
+        pthread_kill(thread, SIGINT);
     }
+    pthread_join(thread, nullptr);
     return success;
 }