Don't use "renderer->viewport" in back-ends

[1bsyl]

Before some future modification to viewport / cliprect, some "simplication".
Don't use "renderer->viewport" in back-ends but use the one that comes from SETVIEWPORT cmd

• tested for the software renderer.
• not tested for D3D11

[sezero]

We have -Wshadow warnings - is the following OK?

diff --git a/src/render/software/SDL_render_sw.c b/src/render/software/SDL_render_sw.c
index 6ce921a..1aaffac 100644
--- a/src/render/software/SDL_render_sw.c
+++ b/src/render/software/SDL_render_sw.c
@@ -862,7 +862,6 @@ SW_RunCommandQueue(SDL_Renderer * renderer, SDL_RenderCommand *cmd, void *vertic
 
                     /* Apply viewport */
                     if (drawstate.viewport->x || drawstate.viewport->y) {
-                        int i;
                         SDL_Point vp;
                         vp.x = drawstate.viewport->x;
                         vp.y = drawstate.viewport->y;
@@ -886,7 +885,6 @@ SW_RunCommandQueue(SDL_Renderer * renderer, SDL_RenderCommand *cmd, void *vertic
 
                     /* Apply viewport */
                     if (drawstate.viewport->x || drawstate.viewport->y) {
-                        int i;
                         SDL_Point vp;
                         vp.x = drawstate.viewport->x;
                         vp.y = drawstate.viewport->y;

[1bsyl]

@sezero yes it's ok!

[sezero]

Applied

[1bsyl]

Thanks !