ath10k: remove unnecessary code

The array fields in struct wmi_start_scan_arg that are checked here are
fixed size arrays so they can never be NULL.

Change-Id: I5c80a9758328df2eff1fa7c4bb433d0370f67143
Addresses-Coverity-ID: 1260031
Cc: Arend Van Spriel <arend.vanspriel@broadcom.com>
Cc: Kalle Valo <kvalo@qca.qualcomm.com>
Signed-off-by: Gustavo A. R. Silva <garsilva@embeddedor.com>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>
Git-repo: https://source.codeaurora.org/quic/la/kernel/msm-4.4


Git-commit: 8c1f20815231edf1ed2b7133ea07ea94ca31db05
Signed-off-by: Swetha Chikkaboraiah <schikk@codeaurora.org>