Prefer assignment to memcpy when either will do.

Prefer assignment to memcpy when either will do.

* lib-src/pop.c (socket_connection) [HAVE_GETADDRINFO]:
* src/bidi.c (bidi_push_it, bidi_pop_it):
* src/fns.c (copy_hash_table):
* src/image.c (define_image_type):
* src/keyboard.c (kbd_buffer_store_event_hold):
* src/process.c (Fprocess_send_eof):
* src/xfaces.c (x_create_gc) [HAVE_NS]:
* src/xgselect.c (xg_select):
Use assignment, not memcpy, as either will do here, and assignment is
more likely to catch type errors.