Fixes _hello in a bunch of places

pyhello.c:29:12: error: '_hello' undeclared (first use in this function)
pyhello.c:23:5: error: '_hellomethods' undeclared here (not in a function)
pyhello.c:14:20: warning: 'hellomethods' defined but not used [-Wunused-variable]
pyhello.c:18:27: warning: 'hellomodule' defined but not used [-Wunused-variable]

NOT FIXED: ImportError: ./_hello.cpython-32mu.so: undefined symbol: hello