[CLEANUP] remove 65 useless NULL checks before free

C specification clearly states that free(NULL) is a no-op.
So remove useless checks before calling free.
diff --git a/src/ev_sepoll.c b/src/ev_sepoll.c
index 70b1065..9fedbdc 100644
--- a/src/ev_sepoll.c
+++ b/src/ev_sepoll.c
@@ -541,12 +541,9 @@
  */
 REGPRM1 static void _do_term(struct poller *p)
 {
-	if (fd_list)
-		free(fd_list);
-	if (spec_list)
-		free(spec_list);
-	if (epoll_events)
-		free(epoll_events);
+	free(fd_list);
+	free(spec_list);
+	free(epoll_events);
 
 	close(epoll_fd);
 	epoll_fd = 0;