More ticket #399: on_request_complete() callback does not release the mutex in some cases

git-svn-id: https://svn.pjsip.org/repos/pjproject/trunk@1524 74dad513-b988-da41-8d7b-12977e46ad98
diff --git a/pjnath/src/pjnath/nat_detect.c b/pjnath/src/pjnath/nat_detect.c
index 9fd669c..e6736ea 100644
--- a/pjnath/src/pjnath/nat_detect.c
+++ b/pjnath/src/pjnath/nat_detect.c
@@ -533,7 +533,7 @@
 		  test_id));
 	end_session(sess, PJ_STATUS_FROM_STUN_CODE(PJ_STUN_SC_SERVER_ERROR),
 		    PJ_STUN_NAT_TYPE_ERR_UNKNOWN);
-	return;
+	goto on_return;
     }
 
     PJ_LOG(5,(sess->pool->obj_name, "Completed %s, status=%d",
@@ -556,7 +556,7 @@
     }
 
     if (test_completed(sess)<3 || test_completed(sess)!=test_executed(sess))
-	return;
+	goto on_return;
 
     /* Handle the test result according to RFC 3489 page 22:
 
@@ -748,6 +748,7 @@
 	break;
     }
 
+on_return:
     pj_mutex_unlock(sess->mutex);
 }