libvlc compile warnings resolved

src/control/input.c

@@ -44,7 +44,7 @@ input_thread_t *libvlc_get_input_thread( libvlc_input_t *p_input,
     if( !p_input )
     {
         libvlc_exception_raise( p_e, "Input is NULL" );
-        return -1;
+        return NULL;
     }
 
     p_input_thread = (input_thread_t*)vlc_object_get(

src/control/video.c

@@ -154,7 +154,7 @@ libvlc_video_take_snapshot( libvlc_input_t *p_input, char *psz_filepath,
     if( !p_input_thread )
     {
         libvlc_exception_raise( p_e, "Input does not exist" );
-        return NULL;
+        return;
     }
    
     snprintf( path, 255, "%s", psz_filepath );