iwlwifi: mvm: remove memset of kek_kck command

iwl_mvm_wowlan_program_keys is now setting data directly in
the KEK_KCK command, and the memset is clearing this later,
causing the data to be incomplete.

Just remove the memory clearing, the structure is local and
cleared in the declaration.

Signed-off-by: Sara Sharon <sara.sharon@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/iwlwifi.20201008181047.0f355b4578c5.Ifbb76a2814925f215a2c889c1792d46d5bd66ab8@changeid