cxl/feature: Update out_len in set feature failure case

CXL subsystem supports userspace to configure features via fwctl
interface, it will configure features by using Set Feature command.
Whatever Set Feature succeeds or fails, CXL driver always needs to
return a structure fwctl_rpc_cxl_out to caller, and returned size is
updated in a out_len parameter. The out_len should be updated not only
when the set feature succeeds, but also when the set feature fails.

Fixes: eb5dfcb ("cxl: Add support to handle user feature commands for set feature")
Signed-off-by: Li Ming <ming.li@zohomail.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Link: https://patch.msgid.link/20250410024521.514095-1-ming.li@zohomail.com
Signed-off-by: Dave Jiang <dave.jiang@intel.com>

Author: MingLi-4

drivers/cxl/core/features.c

@@ -528,13 +528,13 @@ static void *cxlctl_set_feature(struct cxl_features_state *cxlfs,
 	rc = cxl_set_feature(cxl_mbox, &feat_in->uuid,
 			     feat_in->version, feat_in->feat_data,
 			     data_size, flags, offset, &return_code);
+	*out_len = sizeof(*rpc_out);
 	if (rc) {
 		rpc_out->retval = return_code;
 		return no_free_ptr(rpc_out);
 	}
 
 	rpc_out->retval = CXL_MBOX_CMD_RC_SUCCESS;
-	*out_len = sizeof(*rpc_out);
 
 	return no_free_ptr(rpc_out);
 }