drop trailing slash for catalog directory on opm alpha generate dockerfile (#831)

Signed-off-by: Ankita Thomas <[email protected]>
Upstream-repository: operator-registry
Upstream-commit: 8e4557f1c5bc3288b91c79cebb1b14e44e59c737

Author: ankitathomas

staging/operator-registry/cmd/opm/alpha/generate/cmd.go

@@ -44,7 +44,7 @@ When specifying extra labels, note that if duplicate keys exist, only the last
 value of each duplicate key will be added to the generated Dockerfile.
 `,
 		RunE: func(_ *cobra.Command, args []string) error {
-			fromDir := args[0]
+			fromDir := filepath.Clean(args[0])
 
 			extraLabels, err := parseLabels(extraLabelStrs)
 			if err != nil {