azure: Fix error messages in available IP code

Fixing the error messages in the check for available IPs.
The error message is always empty since there was no error
but there are no IPs available.

pkg/asset/manifests/azure/cluster.go

@@ -283,7 +283,7 @@ func getNextAvailableIP(ctx context.Context, installConfig *installconfig.Instal
 		}
 	}
 	if ipAvail.AvailableIPAddresses == nil || len(*ipAvail.AvailableIPAddresses) == 0 {
-		return "", fmt.Errorf("failed to get an available IP in given virtual network for LB: %w", err)
+		return "", fmt.Errorf("failed to get an available IP in given virtual network for LB: this error may be caused by lack of necessary permissions")
 	}
 	for _, ip := range *ipAvail.AvailableIPAddresses {
 		for _, cidrRange := range machineCidr {
@@ -296,5 +296,5 @@ func getNextAvailableIP(ctx context.Context, installConfig *installconfig.Instal
 			}
 		}
 	}
-	return "", fmt.Errorf("failed to get available IP in given machine network: %w", err)
+	return "", fmt.Errorf("failed to get available IP in given machine network: this error may be caused by lack of necessary permissions")
 }