hack(6): Fix a segfault that occurs when ASLR is enabled

Prior to this change, savenames() would store "objects" in save files as a
blob, and restnames() would load it and overwrite "objects". But since
objclass::oc_name and oc_descr are pointers to string constants, they would
be invalid when the next time the process is spawned, and opening the
inventory would crash by dereferencing invalid pointers.

(pho)