common, input_common, network: fix warnings

src/common/string_util.cpp

@@ -170,7 +170,7 @@ static std::wstring CPToUTF16(u32 code_page, const std::string& input) {
         MultiByteToWideChar(code_page, 0, input.data(), static_cast<int>(input.size()), nullptr, 0);
 
     if (size == 0) {
-        return L"";
+        return {};
     }
 
     std::wstring output(size, L'\0');

src/input_common/sdl/sdl_impl.cpp

@@ -1018,7 +1018,7 @@ public:
     }
 
     Common::ParamPackage GetNextInput() override {
-        SDL_Event event;
+        SDL_Event event{};
         while (state.event_queue.Pop(event)) {
             if (event.type != SDL_JOYAXISMOTION || std::abs(event.jaxis.value / 32767.0) < 0.5) {
                 continue;

src/network/packet.cpp

@@ -85,42 +85,42 @@ Packet& Packet::operator>>(u8& out_data) {
 }
 
 Packet& Packet::operator>>(s16& out_data) {
-    s16 value;
+    s16 value = 0;
     Read(&value, sizeof(value));
     out_data = ntohs(value);
     return *this;
 }
 
 Packet& Packet::operator>>(u16& out_data) {
-    u16 value;
+    u16 value = 0;
     Read(&value, sizeof(value));
     out_data = ntohs(value);
     return *this;
 }
 
 Packet& Packet::operator>>(s32& out_data) {
-    s32 value;
+    s32 value = 0;
     Read(&value, sizeof(value));
     out_data = ntohl(value);
     return *this;
 }
 
 Packet& Packet::operator>>(u32& out_data) {
-    u32 value;
+    u32 value = 0;
     Read(&value, sizeof(value));
     out_data = ntohl(value);
     return *this;
 }
 
 Packet& Packet::operator>>(s64& out_data) {
-    s64 value;
+    s64 value = 0;
     Read(&value, sizeof(value));
     out_data = ntohll(value);
     return *this;
 }
 
 Packet& Packet::operator>>(u64& out_data) {
-    u64 value;
+    u64 value = 0;
     Read(&value, sizeof(value));
     out_data = ntohll(value);
     return *this;