[Coverity] Fix some possible NULL-pointer dereferences

renderdoccmd/renderdoccmd.cpp

@@ -156,10 +156,13 @@ int renderdoccmd(int argc, char **argv)
 			ReplayRenderer *renderer = NULL;
 			auto status = RENDERDOC_CreateReplayRenderer(argv[1], &progress, &renderer);
 
-			if(renderer && status == eReplayCreate_Success)
-				DisplayRendererPreview(renderer);
+			if(renderer)
+			{
+				if(status == eReplayCreate_Success)
+					DisplayRendererPreview(renderer);
 
-			ReplayRenderer_Shutdown(renderer);
+				ReplayRenderer_Shutdown(renderer);
+			}
 			return 0;
 		}
 		// dump the image from a logfile

renderdoccmd/renderdoccmd_win32.cpp

@@ -352,7 +352,7 @@ int WINAPI wWinMain(_In_ HINSTANCE hInst,
 					fn = strchr(fn, '/');
 					if(fn) fn++;
 
-					if(*fn)
+					if(fn && *fn)
 					{
 						wchar_t conv[MAX_PATH] = {0};
 						wchar_t *wfn = conv;