windows: Fixed some Visual Studio warnings about shadowed variables.

Fixes Bugzilla #4118.

src/joystick/windows/SDL_mmjoystick.c

@@ -366,10 +366,7 @@ SDL_SYS_JoystickUpdate(SDL_Joystick * joystick)
 
     /* joystick hat events */
     if (joyinfo.dwFlags & JOY_RETURNPOV) {
-        Uint8 pos;
-
-        pos = TranslatePOV(joyinfo.dwPOV);
-        SDL_PrivateJoystickHat(joystick, 0, pos);
+        SDL_PrivateJoystickHat(joystick, 0, TranslatePOV(joyinfo.dwPOV));
     }
 }
 

src/video/windows/SDL_windowswindow.c

@@ -219,8 +219,6 @@ SetupWindowData(_THIS, SDL_Window * window, HWND hwnd, HWND parent, SDL_bool cre
             if ((window->windowed.w && window->windowed.w != w) || (window->windowed.h && window->windowed.h != h)) {
                 /* We tried to create a window larger than the desktop and Windows didn't allow it.  Override! */
                 int x, y;
-                int w, h;
-
                 /* Figure out what the window area will be */
                 WIN_AdjustWindowRect(window, &x, &y, &w, &h, SDL_FALSE);
                 SetWindowPos(hwnd, HWND_NOTOPMOST, x, y, w, h, SWP_NOCOPYBITS | SWP_NOZORDER | SWP_NOACTIVATE);