Initialize variable to appease compiler warning

src/gpu/vk/GrVkPipelineStateBuilder.cpp

 /*
 * Copyright 2016 Google Inc.
 *
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 */
 
 #include "vk/GrVkPipelineStateBuilder.h"
 
 #include "vk/GrVkGpu.h"
@@ skipping 81 matching lines @@
             shaderString.append("\n");
         }
     }
 
     VkShaderModuleCreateInfo moduleCreateInfo;
     memset(&moduleCreateInfo, 0, sizeof(VkShaderModuleCreateInfo));
     moduleCreateInfo.sType = VK_STRUCTURE_TYPE_SHADER_MODULE_CREATE_INFO;
     moduleCreateInfo.pNext = nullptr;
     moduleCreateInfo.flags = 0;
 
-    shaderc_compilation_result_t result;
+    shaderc_compilation_result_t result = nullptr;
 
     if (gpu->vkCaps().canUseGLSLForShaderModule()) {
         moduleCreateInfo.codeSize = strlen(shaderString.c_str());
         moduleCreateInfo.pCode = (const uint32_t*)shaderString.c_str();
     } else {
 
         shaderc_compiler_t compiler = gpu->shadercCompiler();
 
         shaderc_compile_options_t options = shaderc_compile_options_initialize();
         shaderc_compile_options_set_forced_version_profile(options, 140, shaderc_profile_none);
@@ skipping 182 matching lines @@
                                  dsLayout,
                                  fUniformHandles,
                                  fUniformHandler.fUniforms,
                                  fUniformHandler.fCurrentVertexUBOOffset,
                                  fUniformHandler.fCurrentFragmentUBOOffset,
                                  numSamplers,
                                  fGeometryProcessor,
                                  fXferProcessor,
                                  fFragmentProcessors);
 }