wifi: iwlwifi: mvm: fix assert on suspend

wifi: iwlwifi: mvm: fix assert on suspend

After using DEFINE_RAW_FLEX, cmd is a pointer to iwl_rxq_sync_cmd,
and not a variable containing both the command and notification.
Adjust hcmd->data and hcmd->len assignment as well.

Fixes: 7438843df8cf ("wifi: iwlwifi: mvm: Avoid -Wflex-array-member-not-at-end warning")
Signed-off-by: Miri Korenblit <miriam.rachel.korenblit@intel.com>
Link: https://patch.msgid.link/20250604031321.2277481-2-miriam.rachel.korenblit@intel.com
Signed-off-by: Miri Korenblit <miriam.rachel.korenblit@intel.com>