[core] remove fdevent fcntl_set hook

(could have been removed in 2010 with commit 38f2d1dd
 which removed fdevent_linux_rtsig.c)

src/fdevent.c

@@ -301,15 +301,12 @@ void fdevent_clrfd_cloexec(int fd) {
 #endif
 }
 
-int fdevent_fcntl_set(fdevents *ev, int fd) {
-	return ((ev) && (ev->fcntl_set)) ? ev->fcntl_set(ev, fd) : 0;
-}
-
 int fdevent_fcntl_set_nb(fdevents *ev, int fd) {
-	if ((ev) && (ev->fcntl_set)) return ev->fcntl_set(ev, fd);
+	UNUSED(ev);
 #ifdef O_NONBLOCK
 	return fcntl(fd, F_SETFL, O_NONBLOCK | O_RDWR);
 #else
+	UNUSED(fd);
 	return 0;
 #endif
 }
@@ -322,7 +319,7 @@ int fdevent_fcntl_set_nb_cloexec(fdevents *ev, int fd) {
 int fdevent_fcntl_set_nb_cloexec_sock(fdevents *ev, int fd) {
 #if defined(SOCK_CLOEXEC) && defined(SOCK_NONBLOCK)
 	if (use_sock_cloexec)
-		return ((ev) && (ev->fcntl_set)) ? ev->fcntl_set(ev, fd) : 0;
+		return 0;
 #endif
 	return fdevent_fcntl_set_nb_cloexec(ev, fd);
 }

src/fdevent.h

@@ -178,8 +178,6 @@ typedef struct fdevents {
 	int (*event_next_fdndx)(struct fdevents *ev, int ndx);
 
 	int (*poll)(struct fdevents *ev, int timeout_ms);
-
-	int (*fcntl_set)(struct fdevents *ev, int fd);
 } fdevents;
 
 fdevents *fdevent_init(struct server *srv, size_t maxfds, int type);
@@ -208,7 +206,6 @@ void fdevent_sched_run(struct server *srv, fdevents *ev);
 
 void fdevent_setfd_cloexec(int fd);
 void fdevent_clrfd_cloexec(int fd);
-int fdevent_fcntl_set(fdevents *ev, int fd);
 int fdevent_fcntl_set_nb(fdevents *ev, int fd);
 int fdevent_fcntl_set_nb_cloexec(fdevents *ev, int fd);
 int fdevent_fcntl_set_nb_cloexec_sock(fdevents *ev, int fd);

src/gw_backend.c

@@ -1722,12 +1722,6 @@ static handler_t gw_write_request(server *srv, gw_handler_ctx *hctx) {
 
         fdevent_register(srv->ev, hctx->fd, gw_handle_fdevent, hctx);
 
-        if (-1 == fdevent_fcntl_set(srv->ev, hctx->fd)) {
-            log_error_write(srv, __FILE__, __LINE__, "ss",
-                            "fcntl failed:", strerror(errno));
-            return HANDLER_ERROR;
-        }
-
         if (hctx->proc->is_local) {
             hctx->pid = hctx->proc->pid;
         }