wlan: Invalid Staid is sent to HDD

During reassociation to associated AP,invalid staid is getting
passed to HDD from CSR and HDD is using the same to update
the adpater address in HDD context and causing a memory
corruption.

As part of this change updated the staId at CSR and added
condition checks at HDD layer before updating the HDD context.

Change-Id: I5f057caac5f766c6c95332484e531366f68a49dd
CRs-Fixed: 681249