Silence the last two C4996 warnings in our code

hook_registry.cpp still used strncpy for the hook-name copy (the same
class the log-ring fix addressed) -- replace with a bounded memcpy.
coop_vk_layer.cpp's debug logger used _wfopen -- switch to _wfopen_s.
Both were the only remaining C4996s in our own code.

hook/src/hook_registry.cpp

@@ -1,5 +1,6 @@
 #include "hook_registry.hpp"
 
+#include <algorithm>
 #include <atomic>
 #include <cstring>
 #include <mutex>
@@ -35,8 +36,9 @@ int hook_register(const char* name, std::uint32_t subsystem)
 		return -1; // table full
 	}
 	Slot& s = g_slots[count];
-	std::strncpy(s.name, name, sizeof(s.name) - 1);
+	const std::size_t len = std::min(std::strlen(name), sizeof(s.name) - 1);
-	s.name[sizeof(s.name) - 1] = '\0';
+	std::memcpy(s.name, name, len);
+	s.name[len] = '\0';
 	s.subsystem.store(subsystem, std::memory_order_relaxed);
 	s.installed.store(0, std::memory_order_relaxed);
 	s.calls.store(0, std::memory_order_relaxed);

vk_layer/coop_vk_layer.cpp

@@ -151,8 +151,8 @@ void logvk(const char* fmt, ...)
 	if (GetTempPathW(MAX_PATH, dir) == 0) {
 		return;
 	}
-	FILE* f = _wfopen((std::wstring(dir) + L"coop_vk_layer.log").c_str(), L"a");
+	FILE* f = nullptr;
-	if (f == nullptr) {
+	if (_wfopen_s(&f, (std::wstring(dir) + L"coop_vk_layer.log").c_str(), L"a") != 0 || f == nullptr) {
 		return;
 	}
 	va_list ap;