qcacld-3.0: Resolve memleak in hdd_configure_sar index

In hdd configure sar index api if the FW supported version is not
SAR_VERSION_2, in that case there is a mem leak issue as the
memory is allocated for sar_command is before the fw sar version
check and in case of fw sar version check failed, memory allocated
for sar command is not freed.

To resolve above issue, move the version check before the memory
allocation for sar command.

Change-Id: I1d5e6bad63134c89ac456c3247eebad79e8f8c79
CRs-Fixed: 2618648