zink: extract resolve surface init to separate function

Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/35477>

src/gallium/drivers/zink/zink_context.c

@@ -4010,19 +4010,8 @@ zink_set_framebuffer_state(struct pipe_context *pctx,
       zink_resource(psurf->texture)->fb_binds |= BITFIELD_BIT(PIPE_MAX_COLOR_BUFS);
    }
 
-   if (ctx->fb_state.resolve) {
-      struct zink_resource *res = zink_resource(ctx->fb_state.resolve);
-      if (!res->surface) {
-         struct pipe_surface tmpl = {0};
-         tmpl.format = res->base.b.format;
-         zink_screen_lock_context(screen);
-         res->surface = screen->copy_context->base.create_surface(&screen->copy_context->base, &res->base.b, &tmpl);
-         zink_screen_unlock_context(screen);
-         /* delete extra ref: the resource controls the surface lifetime, not the other way around */
-         struct pipe_resource *pres = ctx->fb_state.resolve;
-         pipe_resource_reference(&pres, NULL);
-      }
-   }
+   if (ctx->fb_state.resolve)
+      zink_surface_resolve_init(screen, zink_resource(ctx->fb_state.resolve));
    rebind_fb_state(ctx, NULL, true);
    ctx->fb_state.samples = MAX2(samples, 1);
    if (ctx->fb_state.width != w || ctx->fb_state.height != h)

src/gallium/drivers/zink/zink_surface.c

@@ -477,3 +477,18 @@ zink_surface_swapchain_update(struct zink_context *ctx, struct zink_surface *sur
    /* the current swapchain imageview is now the view for the current swapchain image */
    surface->image_view = surface->swapchain[res->obj->dt_idx];
 }
+
+void
+zink_surface_resolve_init(struct zink_screen *screen, struct zink_resource *res)
+{
+   if (res->surface)
+      return;
+   struct pipe_surface tmpl = {0};
+   tmpl.format = res->base.b.format;
+   zink_screen_lock_context(screen);
+   res->surface = screen->copy_context->base.create_surface(&screen->copy_context->base, &res->base.b, &tmpl);
+   zink_screen_unlock_context(screen);
+   /* delete extra ref: the resource controls the surface lifetime, not the other way around */
+   struct pipe_resource *pres = &res->base.b;
+   pipe_resource_reference(&pres, NULL);
+}

src/gallium/drivers/zink/zink_surface.h

@@ -82,4 +82,7 @@ zink_surface_create_null(struct zink_context *ctx, enum pipe_texture_target targ
 
 void
 zink_surface_swapchain_update(struct zink_context *ctx, struct zink_surface *surface);
+void
+zink_surface_resolve_init(struct zink_screen *screen, struct zink_resource *res);
+
 #endif