wifi: iwlwifi: don't use an uninitialized variable

wifi: iwlwifi: don't use an uninitialized variable

[ Upstream commit c46fcc6e43d617252945e706f04e5f82a59f2b8e ]

Don't use variable err uninitialized.
The reason for removing the check instead of initializing it
in the beginning of the function is because that way
static checkers will be able to catch issues if we do something
wrong in the future.

Fixes: bf976c814c86 ("wifi: iwlwifi: mvm: implement link change ops")
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/20230830112059.431b01bd8779.I31fc4ab35f551b85a10f974a6b18fc30191e9c35@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>