Resolve unused-but-set-variable introduced by c608ca35 and remove a line of redundant code.

src/switch_core.c

@@ -1577,12 +1577,8 @@ SWITCH_DECLARE(switch_status_t) switch_core_init(switch_core_flag_t flags, switc
 static void handle_SIGCHLD(int sig)
 {
 	int status = 0;
-	int pid = 0;
 
-	if (sig) {};
-
-	pid = wait(&status);
-	
+	wait(&status);
 	return;
 }
 #endif