hp malloc: fix pkg max_real_used computation in hp_info()

	* update_shm_stats() should not be called at all
(cherry picked from commit e56f327aea403aae6982bbb404b2c9f6f4c146a3)
hp malloc: properly release the hash lock on redundant shm_reallocs

	* e.g. shm_realloc(shm_malloc(16), 16);
(cherry picked from commit 4148c3f19d99919bb06aff3d7370cbfb96c40374)