wifi: iwlwifi: mvm: remove not needed initializations

In iwl_mvm_add_sta() we're initializing the new allocated mvm_sta.
We are setting some fields to zero even though it was allocated with
kzalloc, for the case of HW restart. But in such a case we will never
get to this initializations due to the goto statement that we have in
this case. Remove these initializations.

Signed-off-by: Miri Korenblit <miriam.rachel.korenblit@intel.com>
Signed-off-by: Gregory Greenman <gregory.greenman@intel.com>
Link: https://lore.kernel.org/r/20230320122330.c0b4d1e986a5.I6959bf1aca74c865e3c1edbf711f5fe8fb8c0c9f@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>