Use perror instead of our own crapily-implemented version.

Yay standards.

capture.c

@@ -183,7 +183,7 @@ int stream_events(char* mouse_path, char* keyboard_path, int hotkey_scancode) {
 		for(int i = 0; i < event_count; i++) {
 			int result = read(events[i].data.fd, &i_event, sizeof(struct input_event));
 			if(result < 0) {
-				fprintf(stderr, "Failed to read an event: %d", errno);
+				perror("Failed to read an event");
 				return 1;
 			}