devlink: Fix error handling in param and info_get dumpit cb

If any of the param or info_get op returns error, dumpit cb is
skipping to dump remaining params or info_get ops for all the
drivers.

Fix to not return if any of the param/info_get op returns error
as not supported and continue to dump remaining information.

v2: Modify the patch to return error, except for params/info_get
op that return -EOPNOTSUPP as suggested by Andrew Lunn. Also, modify
commit message to reflect the same.

Cc: Andrew Lunn <andrew@lunn.ch>
Cc: Jiri Pirko <jiri@mellanox.com>
Cc: Michael Chan <michael.chan@broadcom.com>
Signed-off-by: Vasundhara Volam <vasundhara-v.volam@broadcom.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/core/devlink.c

@@ -3172,7 +3172,7 @@ static int devlink_nl_cmd_param_get_dumpit(struct sk_buff *msg,
 						    NETLINK_CB(cb->skb).portid,
 						    cb->nlh->nlmsg_seq,
 						    NLM_F_MULTI);
-			if (err) {
+			if (err && err != -EOPNOTSUPP) {
 				mutex_unlock(&devlink->lock);
 				goto out;
 			}
@@ -3432,7 +3432,7 @@ static int devlink_nl_cmd_port_param_get_dumpit(struct sk_buff *msg,
 						NETLINK_CB(cb->skb).portid,
 						cb->nlh->nlmsg_seq,
 						NLM_F_MULTI);
-				if (err) {
+				if (err && err != -EOPNOTSUPP) {
 					mutex_unlock(&devlink->lock);
 					goto out;
 				}
@@ -4088,7 +4088,7 @@ static int devlink_nl_cmd_info_get_dumpit(struct sk_buff *msg,
 					   cb->nlh->nlmsg_seq, NLM_F_MULTI,
 					   cb->extack);
 		mutex_unlock(&devlink->lock);
-		if (err)
+		if (err && err != -EOPNOTSUPP)
 			break;
 		idx++;
 	}