render: fix some static analysis warnings.
diff --git a/src/render/SDL_render.c b/src/render/SDL_render.c
index 7f2b47c..2d08725 100644
--- a/src/render/SDL_render.c
+++ b/src/render/SDL_render.c
@@ -2658,6 +2658,7 @@ SDL_RenderFillRect(SDL_Renderer * renderer, const SDL_Rect * rect)
frect.h = (float) rect->h;
} else {
SDL_Rect r;
+ SDL_zero(r);
SDL_RenderGetViewport(renderer, &r);
frect.x = 0.0f;
frect.y = 0.0f;
@@ -2677,6 +2678,7 @@ SDL_RenderFillRectF(SDL_Renderer * renderer, const SDL_FRect * rect)
/* If 'rect' == NULL, then outline the whole surface */
if (!rect) {
SDL_Rect r;
+ SDL_zero(r);
SDL_RenderGetViewport(renderer, &r);
frect.x = 0.0f;
frect.y = 0.0f;