wifi: iwlwifi: mvm: return uid from iwl_mvm_build_scan_cmd

wifi: iwlwifi: mvm: return uid from iwl_mvm_build_scan_cmd

This function is supposed to return a uid on success, and an errno in
failure.
But it currently returns the return value of the specific cmd version
handler, which in turn returns 0 on success and errno otherwise.
This means that on success, iwl_mvm_build_scan_cmd will return 0
regardless if the actual uid.
Fix this by returning the uid if the handler succeeded.

Fixes: 687db6ff5b70 ("iwlwifi: scan: make new scan req versioning flow")
Signed-off-by: Miri Korenblit <miriam.rachel.korenblit@intel.com>
Reviewed-by: Ilan Peer <ilan.peer@intel.com>
Link: https://msgid.link/20240415114847.5e2d602b3190.I4c4931021be74a67a869384c8f8ee7463e0c7857@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>