qcacld-3.0: Fix pointer dereference condition

In the API csr_roam_read_tsf, the driver assigns
pBssDescription to handoffNode.pBssDescription but
it may happen that handoffNode.pBssDescription was NULL,
which would result in a pointer dereference.

Fix is to assign pBssDescription, and perform related
operation with pBssDescription after valid check for
handoffNode.pBssDescription.

Change-Id: I2b9ff44e22aa86b1430d8a624bac2f0e50b91738
CRs-Fixed: 2259253
1 file changed