Fix framebuffer created for reflection probe in mobile renderer

[BastiaanOlij]

In the mobile renderer, if reflection probes are used, we were getting the following GPU validation error:

VUID-vkCmdEndRenderPass-None-00910(ERROR / SPEC): msgNum: 2050775817 - Validation Error: [ VUID-vkCmdEndRenderPass-None-00910 ] Object 0: handle = 0x1aa2db36d50, type = VK_OBJECT_TYPE_COMMAND_BUFFER; Object 1: handle = 0x3e5a36000000fffc, type = VK_OBJECT_TYPE_RENDER_PASS; | MessageID = 0x7a3c5b09 | vkCmdEndRenderPass():  Called before reaching final subpass. The Vulkan spec states: The current subpass index must be equal to the number of subpasses in the render pass minus one (https://vulkan.lunarg.com/doc/view/1.3.275.0/windows/1.3-extensions/vkspec.html#VUID-vkCmdEndRenderPass-None-00910)
    Objects: 2
       [0]  0x1aa2db36d50, type: 6, name: NULL
       [1]  0x3e5a36000000fffc, type: 18, name: NULL
drivers\vulkan\vulkan_context.cpp:267 - VALIDATION - Message Id Number: 2050775817 | Message Id Name: VUID-vkCmdEndRenderPass-None-00910
	Validation Error: [ VUID-vkCmdEndRenderPass-None-00910 ] Object 0: handle = 0x1aa2db36d50, type = VK_OBJECT_TYPE_COMMAND_BUFFER; Object 1: handle = 0x3e5a36000000fffc, type = VK_OBJECT_TYPE_RENDER_PASS; | MessageID = 0x7a3c5b09 | vkCmdEndRenderPass():  Called before reaching final subpass. The Vulkan spec states: The current subpass index must be equal to the number of subpasses in the render pass minus one (https://vulkan.lunarg.com/doc/view/1.3.275.0/windows/1.3-extensions/vkspec.html#VUID-vkCmdEndRenderPass-None-00910)
	Objects - 2
		Object[0] - VK_OBJECT_TYPE_COMMAND_BUFFER, Handle 1830422801744
		Object[1] - VK_OBJECT_TYPE_RENDER_PASS, Handle 4492962951883456508

This is due to a recent improvement in the mobile renderer where we no longer use subpasses to render the opaque, sky and transparent passes but join them into a single pass if possible.

I however forgot to update the code for reflection probes to remove the subpasses here as well.

[BastiaanOlij]

Also removing this, as we've now merged our passes, we can just reuse the framebuffer we fetched at the start.

[clayjohn]

Looks great!

[DarioSamo]

Tested, can confirm this fixes the validation error I was running into.

[YuriSizov]

Thanks!