ug_input: Add missing initializers

Author: mpiatka

src/video_capture/ug_input.cpp

@@ -76,17 +76,17 @@ using std::chrono::steady_clock;
 struct ug_input_state final : public frame_recv_delegate {
         mutex lock;
         queue<pair<struct video_frame *, struct audio_frame *>> frame_queue;
-        struct display *display;
+        struct display *display = nullptr;
 
         void frame_arrived(struct video_frame *f, struct audio_frame *a) override;
         thread         receiver_thread;
         unique_ptr<ultragrid_rtp_video_rxtx> video_rxtx;
-        struct state_audio *audio;
+        struct state_audio *audio = nullptr;
 
         ~ug_input_state() override = default;
 
-        std::chrono::steady_clock::time_point t0;
-        int frames;
+        std::chrono::steady_clock::time_point t0 = {};
+        int frames = 0;
 
         struct common_opts common = { COMMON_OPTS_INIT };
 };