Fixes an issue with blitting of sRGB buffers

Forces using vrend_render_blit_gl if sourceframebuffers is in sRGB
colorspace. Fixes following tests:
dEQP-GLES3.functional.fbo.blit.conversion.srgb8_alpha8_to_rgba8
dEQP-GLES3.functional.fbo.blit.conversion.srgb8_alpha8_to_rgb10_a2
dEQP-GLES3.functional.fbo.blit.conversion.srgb8_alpha8_to_rgba4
dEQP-GLES3.functional.fbo.blit.conversion.srgb8_alpha8_to_rgb5_a1
dEQP-GLES3.functional.fbo.blit.conversion.srgb8_alpha8_to_rgb8
dEQP-GLES3.functional.fbo.blit.conversion.srgb8_alpha8_to_rgb565
dEQP-GLES3.functional.fbo.blit.conversion.srgb8_alpha8_to_rg8
dEQP-GLES3.functional.fbo.blit.conversion.srgb8_alpha8_to_r8

Signed-off-by: Jakob Bornecrantz <jakob@collabora.com>
Reviewed-by: Jakob Bornecrantz <jakob@collabora.com>
Tested-by: Jakob Bornecrantz <jakob@collabora.com>

src/vrend_renderer.c

@@ -5906,6 +5906,9 @@ static void vrend_renderer_blit_int(struct vrend_context *ctx,
        !vrend_format_is_ds(dst_res->base.format))
       use_gl = true;
 
+   if (util_format_is_srgb(src_res->base.format))
+      use_gl = true;
+
    /* different depth formats */
    if (vrend_format_is_ds(src_res->base.format) &&
        vrend_format_is_ds(dst_res->base.format)) {