s/pam_message/pam_response/ (Thanks Tucos)

The previous code didn’t cause any issues since both types (currently!)
have the same size.

i3lock.c

@@ -439,7 +439,7 @@ static int conv_callback(int num_msg, const struct pam_message **msg,
         return 1;
 
     /* PAM expects an array of responses, one for each message */
-    if ((*resp = calloc(num_msg, sizeof(struct pam_message))) == NULL) {
+    if ((*resp = calloc(num_msg, sizeof(struct pam_response))) == NULL) {
         perror("calloc");
         return 1;
     }