examples, ggml : fix GCC compiler warnings (llama/10983)

Warning types fixed (observed under MSYS2 GCC 14.2.0):
* format '%ld' expects argument of type 'long int', but argument has type 'size_t'
* llama.cpp/src/ggml-vulkan/vulkan-shaders/vulkan-shaders-gen.cpp:81:46: warning: missing initializer for member '_STARTUPINFOA::lpDesktop' [-Wmissing-field-initializers]  (emitted for all struct field except first)

Author: peter277

ggml/src/ggml-vulkan/vulkan-shaders/vulkan-shaders-gen.cpp

@@ -78,7 +78,8 @@ void execute_command(const std::string& command, std::string& stdout_str, std::s
     }
 
     PROCESS_INFORMATION pi;
-    STARTUPINFOA si = { sizeof(STARTUPINFOA) };
+    STARTUPINFOA si = {};
+    si.cb = sizeof(STARTUPINFOA);
     si.dwFlags = STARTF_USESTDHANDLES;
     si.hStdOutput = stdout_write;
     si.hStdError = stderr_write;