anv: destroy descriptor sets when pool gets destroyed

Patch maintains a list of sets in the pool and destroys possible remaining sets when pool is destroyed.

As stated in Vulkan spec: "When a pool is destroyed, all descriptor sets allocated from the pool are implicitly freed and become invalid."

This fixes memory leaks spotted with valgrind:

==19622== 96 bytes in 1 blocks are definitely lost in loss record 2 of 3 ==19622== at 0x483880B: malloc (vg_replace_malloc.c:309) ==19622== by 0x495B67E: default_alloc_func (anv_device.c:547) ==19622== by 0x4955E05: vk_alloc (vk_alloc.h:36) ==19622== by 0x4956A8F: anv_multialloc_alloc (anv_private.h:538) ==19622== by 0x4956A8F: anv_CreateDescriptorSetLayout (anv_descriptor_set.c:217)

Signed-off-by: Tapani Pälli tapani.palli@intel.com