FPM: Downgrade occasional "failed to acquire scoreboard" warning

With request timeouts configured, php-fpm occasionally prints the
following warning:

   WARNING: failed to acquire scoreboard

This is happens when php-fpm checks the child scoreboards for timeouts,
but fails to acquire a lock immediately.  As this can (and does) occur
during normal operation, this commit downgrades this to a notice.
Closes #9019.

NEWS

@@ -22,6 +22,8 @@ PHP                                                                        NEWS
 - FPM:
   . Fixed zlog message prepend, free on incorrect address. (Heiko Weber)
   . Fixed possible double free on configuration loading failure. (Heiko Weber).
+  . Fixed on fpm scoreboard occasional warning on acquisition failure.
+    (Felix Wiedemann)
 
 - GD:
   . Fixed bug GH-8848 (imagecopyresized() error refers to the wrong argument).

sapi/fpm/fpm/fpm_request.c

@@ -231,7 +231,7 @@ void fpm_request_check_timed_out(struct fpm_child_s *child, struct timeval *now,
 
 	proc_p = fpm_scoreboard_proc_acquire(child->wp->scoreboard, child->scoreboard_i, 1);
 	if (!proc_p) {
-		zlog(ZLOG_WARNING, "failed to acquire scoreboard");
+		zlog(ZLOG_NOTICE, "failed to acquire scoreboard");
 		return;
 	}