Remove \n from errx and die messages

errx() already appends \n internally. "\n" in the error message will
result in a blank line after the message. die() is just a wrapper around
errx() so it receives the same treatment.

i3-input/main.c

@@ -435,7 +435,7 @@ int main(int argc, char *argv[]) {
     int screen;
     conn = xcb_connect(NULL, &screen);
     if (!conn || xcb_connection_has_error(conn))
-        die("Cannot open display\n");
+        die("Cannot open display");
 
     sockfd = ipc_connect(socket_path);