iwlwifi: mvm: update layout of firmware error dump

The memory was not zeroed - fix that. Also update the
iwl_fw_error_dump_info structure.
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>

drivers/net/wireless/iwlwifi/mvm/mac80211.c

@@ -686,7 +686,7 @@ static void iwl_mvm_fw_error_dump(struct iwl_mvm *mvm)
 	if (trans_len)
 		file_len += trans_len;
 
-	dump_file = vmalloc(file_len);
+	dump_file = vzalloc(file_len);
 	if (!dump_file)
 		return;