simplify logcatd (#19640)

* simplify logcatd

* add assert

* revert opendbc

* revert opendbc
old-commit-hash: 6104e4c09e

selfdrive/logcatd/logcatd_systemd.cc

@@ -36,17 +36,9 @@ int main(int argc, char *argv[]) {
 
     // Wait for new message if we didn't receive anything
     if (r == 0){
-      do {
-        r = sd_journal_wait(journal, 1000 * 1000);
-        assert(r >= 0);
-      } while (r == SD_JOURNAL_NOP && !do_exit);
-
-      if (do_exit) break;
-
-      r = sd_journal_next(journal);
-      assert(r >= 0);
-
-      if (r == 0) continue; // Try again if we still didn't get anything
+      r = sd_journal_wait(journal, 1000 * 1000);
+      assert (r >= 0);
+      continue; // Try again
     }
 
     uint64_t timestamp = 0;