iwlwifi: remove alive start adhoc restart

This code will never trigger, because when
we call this during interface start, neither
priv->vif nor priv->iw_mode conditions will
be true, and when it happens during reset
then priv->vif is also NULL. Also, in both
cases the same code will be executed as part
of iwl_bss_info_changed(), which contains a
copy of this code.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>