Vulkan: fix various simple leaks
commit b43651cf
vulkandisplay: Also free the GSource
NULL checking the main_context does not help as we've just destroyed the
GMainContext and set that field to NULL, not to mention it's unnecessary.
Fixes a leak of display's GSource.
commit 1b7e83c5
vulkandisplay: free the list of windows on destruction
They may not have had an explicit removal from the subclass.
commit 833c596b
vulkan/fullscreenrender: free the attachment descriptions
Fixes a memory leak of the attachment descriptions we receive from the
subclass.
commit fc9f0478
vulkandisplay: fix use-after-free with removal of window
g_list_delete_link() free()'s the list node so any access after that is
a use-after-free.
commit e83df175
vulkan/xcb: display->windows is a list of allocated GWeakRef
Don't access them as plain GstVulkanWindow objects.