WNM: Fix candidates count in BSS Transition Management Request

WNM: Fix candidates count in BSS Transition Management Request

In BSS Transition Management Request frame, it is possible that vendor
specific IEs are included after the candidate list. In this case the
candidates count was incremented for each IE although the candidate list
is already over which could result in adding all zeros candidates into
the neighbor list.

Fix that by incrementing the candidates count only for neighbor report
elements.

Signed-off-by: Avraham Stern <avraham.stern@intel.com>