vo_gpu: un-fix storable fbo format check

The original solution for mpv-player#7017 was sort of a hack, but this hack is no
longer needed because c05e5d9 fixed the underlying issue causing this
error to be spammed in the first place. So just remove the "fix" that
apparently introduced about as many issueas it fixed.

Fixes mpv-player#7719, hopefully.

video/out/gpu/video.c

@@ -3302,8 +3302,7 @@ void gl_video_render_frame(struct gl_video *p, struct vo_frame *frame,
                     const struct ra_format *fmt = fbo.tex->params.format;
                     if (fmt->dummy_format)
                         fmt = p->fbo_format;
-                    if (!fmt->storable && p->fbo_format->storable)
-                        fmt = p->fbo_format; // to be on the safe side
+
                     bool r = ra_tex_resize(p->ra, p->log, &p->output_tex,
                                            fbo.tex->params.w, fbo.tex->params.h,
                                            fmt);