qcacmn: Fix OOB reads in util_gen_new_ie

In util_gen_new_ie, there are several possible out-of-bound reads
with invalid information elements such as improper/missing check when
updating tmp_old, missing check prior to starting while loop and missing
length check.

To fix these OOB issues add and improve length checks in util_gen_new_ie.

Change-Id: I39b9cd82ab6a7bd1a4c8d7cd5039a998a290b85f
CRs-Fixed: 3717568