RDMA/ipoib: Print symbolic error name instead of error code

Utilize the %pe print specifier to get the symbolic error name as a
string (i.e "-ENOMEM") in the log message instead of the error code to
increase its readability.

This change was suggested in
https://lore.kernel.org/all/92972476-0b1f-4d0a-9951-af3fc8bc6e65@suswa.mountain/

Signed-off-by: Christian Heusel <christian@heusel.eu>
Link: https://lore.kernel.org/r/20240111141311.987098-1-christian@heusel.eu
Reviewed-by: Dan Carpenter <dan.carpenter@linaro.org>
Signed-off-by: Leon Romanovsky <leon@kernel.org>

drivers/infiniband/ulp/ipoib/ipoib_multicast.c

@@ -287,8 +287,7 @@ static int ipoib_mcast_join_finish(struct ipoib_mcast *mcast,
 
 	ah = ipoib_create_ah(dev, priv->pd, &av);
 	if (IS_ERR(ah)) {
-		ipoib_warn(priv, "ib_address_create failed %ld\n",
-			   -PTR_ERR(ah));
+		ipoib_warn(priv, "ib_address_create failed %pe\n", ah);
 		/* use original error */
 		return PTR_ERR(ah);
 	}