chore: replace deprecated call

Author: gwossum

cmd/influxd/downgrade/downgrade.go

@@ -75,7 +75,7 @@ influxd binary to boot successfully.
 The target version of the downgrade must be specified, i.e. "influxd downgrade 2.0".
 `,
 		ValidArgs: validDowngradeTargets,
-		Args:      cobra.ExactValidArgs(1),
+		Args:      cobra.MatchAll(cobra.ExactArgs(1), cobra.OnlyValidArgs),
 		RunE: func(cmd *cobra.Command, args []string) error {
 			logconf := &influxlogger.Config{
 				Format: "auto",