fix most of build warnings on openbsd

sorry openbsd people, we're not going to use the snprintf function.

src/backend/backend.c

@@ -194,7 +194,7 @@ bool paint_all_new(session_t *ps, struct managed_win *const t) {
 	auto after_damage_us = (uint64_t)now.tv_sec * 1000000UL + (uint64_t)now.tv_nsec / 1000;
 	log_trace("Getting damage took %" PRIu64 " us", after_damage_us - after_sync_fence_us);
 	if (ps->next_render > 0) {
-		log_verbose("Render schedule deviation: %ld us (%s) %" PRIu64 " %ld",
+		log_verbose("Render schedule deviation: %ld us (%s) %" PRIu64 " %" PRIu64,
 		            labs((long)after_damage_us - (long)ps->next_render),
 		            after_damage_us < ps->next_render ? "early" : "late",
 		            after_damage_us, ps->next_render);

src/config.c

@@ -43,10 +43,7 @@ const char *xdg_config_home(void) {
 			return NULL;
 		}
 
-		xdgh = cvalloc(strlen(home) + strlen(default_dir) + 1);
-
-		strcpy(xdgh, home);
-		strcat(xdgh, default_dir);
+		xdgh = mstrjoin(home, default_dir);
 	} else {
 		xdgh = strdup(xdgh);
 	}

src/picom.c

@@ -210,11 +210,13 @@ collect_vblank_interval_statistics(struct vblank_event *e, void *ud) {
 			if (frame_count == 1) {
 				render_statistics_add_vblank_time_sample(
 				    &ps->render_stats, frame_time);
-				log_trace("Frame count %lu, frame time: %d us, ust: "
-				          "%" PRIu64 "",
+				log_trace("Frame count %" PRIu64 ", frame time: %d us, "
+				          "ust: "
+				          "%" PRIu64,
 				          frame_count, frame_time, e->ust);
 			} else {
-				log_trace("Frame count %lu, frame time: %d us, msc: "
+				log_trace("Frame count %" PRIu64 ", frame time: %d us, "
+				          "msc: "
 				          "%" PRIu64 ", not adding sample.",
 				          frame_count, frame_time, e->ust);
 			}

src/vblank.c

@@ -327,7 +327,7 @@ sgi_video_sync_scheduler_callback(EV_P attr_unused, ev_async *w, int attr_unused
 	};
 	sched->base.vblank_event_requested = false;
 	sched->last_msc = msc;
-	log_verbose("Received vblank event for msc %lu", event.msc);
+	log_verbose("Received vblank event for msc %" PRIu64, event.msc);
 	vblank_scheduler_invoke_callbacks(&sched->base, &event);
 }
 #endif
@@ -411,7 +411,7 @@ static void handle_present_complete_notify(struct present_vblank_scheduler *self
 	auto now_us = (unsigned long)(now.tv_sec * 1000000L + now.tv_nsec / 1000);
 	double delay_sec = 0.0;
 	if (now_us < cne->ust) {
-		log_trace("The end of this vblank is %lu us into the "
+		log_trace("The end of this vblank is %" PRIu64 " us into the "
 		          "future",
 		          cne->ust - now_us);
 		delay_sec = (double)(cne->ust - now_us) / 1000000.0;
@@ -566,4 +566,4 @@ bool vblank_handle_x_events(struct vblank_scheduler *self) {
 		return fn(self);
 	}
 	return true;
-}
+}

src/win.c

@@ -470,7 +470,8 @@ void win_process_update_flags(session_t *ps, struct managed_win *w) {
 	// Whether the window was visible before we process the mapped flag. i.e.
 	// is the window just mapped.
 	bool was_visible = win_is_real_visible(w);
-	log_trace("Processing flags for window %#010x (%s), was visible: %d, flags: %#lx",
+	log_trace("Processing flags for window %#010x (%s), was visible: %d, flags: "
+	          "%#" PRIx64,
 	          w->base.id, w->name, was_visible, w->flags);
 
 	if (win_check_flags_all(w, WIN_FLAGS_MAPPED)) {