zink: always set VkPipelineMultisampleStateCreateInfo::pSampleMask
by initializing this on context creation, we can ensure that the correct value is always here
cc: mesa-stable
fixes: dEQP-GLES31.functional.texture.multisample.samples_1.sample_mask_and_alpha_to_coverage dEQP-GLES31.functional.texture.multisample.samples_1.sample_mask_and_sample_coverage dEQP-GLES31.functional.texture.multisample.samples_1.sample_mask_and_sample_coverage_and_alpha_to_coverage dEQP-GLES31.functional.texture.multisample.samples_1.sample_mask_only dEQP-GLES31.functional.texture.multisample.samples_2.sample_mask_and_alpha_to_coverage dEQP-GLES31.functional.texture.multisample.samples_2.sample_mask_and_sample_coverage dEQP-GLES31.functional.texture.multisample.samples_2.sample_mask_and_sample_coverage_and_alpha_to_coverage dEQP-GLES31.functional.texture.multisample.samples_2.sample_mask_only dEQP-GLES31.functional.texture.multisample.samples_3.sample_mask_and_alpha_to_coverage dEQP-GLES31.functional.texture.multisample.samples_3.sample_mask_and_sample_coverage dEQP-GLES31.functional.texture.multisample.samples_3.sample_mask_and_sample_coverage_and_alpha_to_coverage dEQP-GLES31.functional.texture.multisample.samples_3.sample_mask_only dEQP-GLES31.functional.texture.multisample.samples_4.sample_mask_and_alpha_to_coverage dEQP-GLES31.functional.texture.multisample.samples_4.sample_mask_and_sample_coverage dEQP-GLES31.functional.texture.multisample.samples_4.sample_mask_and_sample_coverage_and_alpha_to_coverage dEQP-GLES31.functional.texture.multisample.samples_4.sample_mask_only