cmd: don't alias context package, and use cliContext for cli.Context

Unfortunately, this is a rather large diff, but perhaps worth a one-time
"rip off the bandaid" for v2. This patch removes the use of "gocontext"
as alias for stdLib's "context", and uses "cliContext" for uses of
cli.context.

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

cmd/ctr/commands/deprecations/deprecations.go

@@ -45,11 +45,11 @@ var listCommand = &cli.Command{
 			Usage: "output format to use (Examples: 'default', 'json')",
 		},
 	},
-	Action: func(context *cli.Context) error {
+	Action: func(cliContext *cli.Context) error {
 		// Suppress automatic warnings, since we print the warnings by ourselves.
 		os.Setenv("CONTAINERD_SUPPRESS_DEPRECATION_WARNINGS", "1")
 
-		client, ctx, cancel, err := commands.NewClient(context)
+		client, ctx, cancel, err := commands.NewClient(cliContext)
 		if err != nil {
 			return err
 		}
@@ -61,7 +61,7 @@ var listCommand = &cli.Command{
 		}
 		wrn := warnings(resp)
 		if len(wrn) > 0 {
-			switch context.String("format") {
+			switch cliContext.String("format") {
 			case "json":
 				commands.PrintAsJSON(warnings(resp))
 				return nil