mod_posix_timer: comply with gcc -pedantic

Thanks to Thierry Panthier for pointing this out.

src/mod/timers/mod_posix_timer/mod_posix_timer.c

@@ -111,7 +111,9 @@ static void timer_signal_handler(int sig, siginfo_t *si, void *cu)
 		if (val >= 0 && val <= MAX_ACTIVE_TIMERS) {
 			uint8_t active_id = (uint8_t)val;
 			/* notify runtime thread that timer identified by active_id has ticked */
-			write(globals.timer_tick_pipe[1], &active_id, 1);
+			if (write(globals.timer_tick_pipe[1], &active_id, 1) == -1) {
+				switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "Error writing to pipe: %s\n", strerror(errno));
+			}
 		}
 	}
 }