anv/tests: Silence unused parameter warnings in main

anv/tests: Silence unused parameter warnings in main

src/intel/vulkan/tests/block_pool_no_free.c: In function ‘main’:
src/intel/vulkan/tests/block_pool_no_free.c:147:14: warning: unused parameter ‘argc’ [-Wunused-parameter]
src/intel/vulkan/tests/block_pool_no_free.c:147:27: warning: unused parameter ‘argv’ [-Wunused-parameter]

src/intel/vulkan/tests/block_pool_grow_first.c: In function ‘main’:
src/intel/vulkan/tests/block_pool_grow_first.c:27:14: warning: unused parameter ‘argc’ [-Wunused-parameter]
src/intel/vulkan/tests/block_pool_grow_first.c:27:27: warning: unused parameter ‘argv’ [-Wunused-parameter]

src/intel/vulkan/tests/state_pool.c: In function ‘main’:
src/intel/vulkan/tests/state_pool.c:36:14: warning: unused parameter ‘argc’ [-Wunused-parameter]
src/intel/vulkan/tests/state_pool.c:36:27: warning: unused parameter ‘argv’ [-Wunused-parameter]

src/intel/vulkan/tests/state_pool_padding.c: In function ‘main’:
src/intel/vulkan/tests/state_pool_padding.c:27:14: warning: unused parameter ‘argc’ [-Wunused-parameter]
src/intel/vulkan/tests/state_pool_padding.c:27:27: warning: unused parameter ‘argv’ [-Wunused-parameter]

src/intel/vulkan/tests/state_pool_no_free.c: In function ‘main’:
src/intel/vulkan/tests/state_pool_no_free.c:115:14: warning: unused parameter ‘argc’ [-Wunused-parameter]
src/intel/vulkan/tests/state_pool_no_free.c:115:27: warning: unused parameter ‘argv’ [-Wunused-parameter]

src/intel/vulkan/tests/state_pool_free_list_only.c: In function ‘main’:
src/intel/vulkan/tests/state_pool_free_list_only.c:35:14: warning: unused parameter ‘argc’ [-Wunused-parameter]
src/intel/vulkan/tests/state_pool_free_list_only.c:35:27: warning: unused parameter ‘argv’ [-Wunused-parameter]

v2: Use 'int main(void)' instead.  Suggested by Jason.

Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/4994>