make example volume import, not import volume

Signed-off-by: Trevor Benson <trevor.benson@scality.com>

cmd/podman/volumes/import.go

@@ -25,7 +25,7 @@ var (
 		Args:              cobra.ExactArgs(2),
 		ValidArgsFunction: common.AutocompleteVolumes,
 		Example: `podman volume import my_vol /home/user/import.tar
-  cat ctr.tar | podman import volume my_vol -`,
+  cat ctr.tar | podman volume import my_vol -`,
 	}
 )