Revert "Fix false crash logs with regression tests (#12783)" (#12793)

This reverts commit dd3455c.

Addressing this turns out to be more complicated than it at first appeared. I realize after more testing that while this patch removed the "false" crash log reports, it broke crash log generally. And attempts at fixing that haven't been very fruitful. Maybe we should look into this in the future, but in the meantime I want to restore things to the previous state so that crash logs will at least be created when there is an actual crash.

Author: bneradt

src/traffic_crashlog/traffic_crashlog.cc

@@ -32,7 +32,6 @@
 #include "tscore/BaseLogFile.h"
 #include "tscore/runroot.h"
 #include "iocore/eventsystem/RecProcess.h"
-#include <poll.h>
 #include <unistd.h>
 
 static int   syslog_mode  = false;
@@ -172,25 +171,6 @@ main(int /* argc ATS_UNUSED */, const char **argv)
     return 0;
   }
 
-  // In wait mode, we need to verify this is a real crash by checking if crash_logger_invoke
-  // sent us signal info via the pipe. If traffic_server just exited normally, the pipe will be
-  // closed with no data, and we should exit without logging a false "crash".
-  if (wait_mode) {
-    // Use poll to check if there's data available on stdin without blocking indefinitely.
-    struct pollfd pfd;
-    pfd.fd     = STDIN_FILENO;
-    pfd.events = POLLIN;
-
-    // Wait briefly for data. If crash_logger_invoke was called, data should already be there.
-    int poll_result = poll(&pfd, 1, 100); // 100ms timeout
-
-    // POLLHUP means the write end of the pipe was closed - normal exit, not crash.
-    // No data or error also means no crash occurred.
-    if (poll_result <= 0 || (pfd.revents & POLLHUP) || !(pfd.revents & POLLIN)) {
-      return 0;
-    }
-  }
-
   runroot_handler(argv);
   Layout::create();
   RecProcessInit(nullptr /* diags */);