Remove unnecessary nullptr checks

[astrelsky]

ghidra/Ghidra/Features/Decompiler/src/decompile/cpp/architecture.cc

Lines 161 to 176 in f6492b9

	if (types != (TypeFactory *)0)
	delete types;
	if (translate != (Translate *)0)
	delete translate;
	if (loader != (LoadImage *)0)
	delete loader;
	if (pcodeinjectlib != (PcodeInjectLibrary *)0)
	delete pcodeinjectlib;
	if (commentdb != (CommentDatabase *)0)
	delete commentdb;
	if (stringManager != (StringManager *)0)
	delete stringManager;
	if (cpool != (ConstantPool *)0)
	delete cpool;
	if (context != (ContextDatabase *)0)
	delete context;

The C++ language GUARANTEES that delete will do nothing if given a nullptr.
https://isocpp.org/wiki/faq/freestore-mgmt#delete-handles-null