Fixed a memory leak in function GL_RenderReadPixels
diff --git a/src/render/opengl/SDL_render_gl.c b/src/render/opengl/SDL_render_gl.c
index df0fd05..85319ea 100644
--- a/src/render/opengl/SDL_render_gl.c
+++ b/src/render/opengl/SDL_render_gl.c
@@ -1438,6 +1438,7 @@
     }
 
     if (!convert_format(data, temp_format, &internalFormat, &format, &type)) {
+        SDL_free(temp_pixels);
         return SDL_SetError("Texture format %s not supported by OpenGL",
                             SDL_GetPixelFormatName(temp_format));
     }