debugger: enforce a null terminated char of a C-string

CID 146728 (#1 of 1): Buffer not null terminated (BUFFER_SIZE_WARNING)
buffer_size_warning: Calling strncpy with a maximum size argument of 128 bytes on destination array mod.name of size 128 bytes might leave the destination string unterminated

pcsx2/DebugTools/SymbolMap.cpp

@@ -241,6 +241,7 @@ void SymbolMap::AddModule(const char *name, u32 address, u32 size) {
 
 	ModuleEntry mod;
 	strncpy(mod.name, name, ARRAY_SIZE(mod.name));
+	mod.name[ARRAY_SIZE(mod.name) - 1] = 0;
 	mod.start = address;
 	mod.size = size;
 	mod.index = (int)modules.size() + 1;