vnc: auth reject cleanup

protocol_client_auth_vnc() has two places where the auth can fail,
with identical code sending the reject message to the client.
Move the common code to the end of the function and make both
error paths jump there.  No functional change.
Signed-off-by: NGerd Hoffmann <kraxel@redhat.com>

ui/vnc.c

@@ -2085,15 +2085,7 @@ static int protocol_client_auth_vnc(VncState *vs, uint8_t *data, size_t len)
 
     if (!vs->vd->password || !vs->vd->password[0]) {
         VNC_DEBUG("No password configured on server");
-        vnc_write_u32(vs, 1); /* Reject auth */
-        if (vs->minor >= 8) {
-            static const char err[] = "Authentication failed";
-            vnc_write_u32(vs, sizeof(err));
-            vnc_write(vs, err, sizeof(err));
-        }
-        vnc_flush(vs);
-        vnc_client_error(vs);
-        return 0;
+        goto reject;
     }
 
     memcpy(response, vs->challenge, VNC_AUTH_CHALLENGE_SIZE);
@@ -2109,14 +2101,7 @@ static int protocol_client_auth_vnc(VncState *vs, uint8_t *data, size_t len)
     /* Compare expected vs actual challenge response */
     if (memcmp(response, data, VNC_AUTH_CHALLENGE_SIZE) != 0) {
         VNC_DEBUG("Client challenge reponse did not match\n");
-        vnc_write_u32(vs, 1); /* Reject auth */
-        if (vs->minor >= 8) {
-            static const char err[] = "Authentication failed";
-            vnc_write_u32(vs, sizeof(err));
-            vnc_write(vs, err, sizeof(err));
-        }
-        vnc_flush(vs);
-        vnc_client_error(vs);
+        goto reject;
     } else {
         VNC_DEBUG("Accepting VNC challenge response\n");
         vnc_write_u32(vs, 0); /* Accept auth */
@@ -2125,6 +2110,17 @@ static int protocol_client_auth_vnc(VncState *vs, uint8_t *data, size_t len)
         start_client_init(vs);
     }
     return 0;
+
+reject:
+    vnc_write_u32(vs, 1); /* Reject auth */
+    if (vs->minor >= 8) {
+        static const char err[] = "Authentication failed";
+        vnc_write_u32(vs, sizeof(err));
+        vnc_write(vs, err, sizeof(err));
+    }
+    vnc_flush(vs);
+    vnc_client_error(vs);
+    return 0;
 }
 
 void start_auth_vnc(VncState *vs)