Currently when transferring SSID information from the nl80211 TLV to
the internal data structure hdd_fill_pmksa_info() always copies
SIR_MAC_MAX_SSID_LENGTH bytes which can overread the buffer. In order
to prevent overread only copy as many bytes as the TLV contains.
Note that the destination buffer passed to hdd_fill_pmksa_info() is
always zero-filled so no additional zeroing of bytes is required.
Change-Id: I1f6773b70e9e728d6b1ce93ca26417348e96844c
CRs-Fixed: 2237462
9c749db62c