cfg80211: use for_each_element() for multi-bssid parsing

Use the new for_each_element() helper here, we cannot use
for_each_subelement() since we have a fixed 1 byte before
the subelements start.

While at it, also fix le16_to_cpup() to be get_unaligned_le16()
since we don't know anything about alignment.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Change-Id: I09771111d7629aa41fd74a853a806b30640afb52
CRs-fixed: 2399972
Git-commit: 1c8745f3ec6f46f5fa99dbcdf92381144ae1b37f
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/jberg/mac80211-next.git


Signed-off-by: Peng Xu <pxu@codeaurora.org>