iwlwifi: mvm: return value for request_ownership

Propagate the value to the user space so it can understand
if the operation failed or not.

Fixes: bfcfdb59 ("iwlwifi: mvm: add vendor commands needed for iwlmei")
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Link: https://lore.kernel.org/r/20220302072715.4885-1-emmanuel.grumbach@intel.com


Signed-off-by: Johannes Berg <johannes.berg@intel.com>