change variable name to something better

Signed-off-by: amghazanfari <a.m.ghazanfari76@gmail.com>

exec.go

@@ -247,15 +247,15 @@ func getProcess(context *cli.Context, bundle string) (*specs.Process, error) {
 	}
 	// Override the user, if passed.
 	if user := context.String("user"); user != "" {
-		uidString, gidString, doesHaveGid := strings.Cut(user, ":")
-		if doesHaveGid {
-			gid, err := strconv.Atoi(gidString)
+		uids, gids, ok := strings.Cut(user, ":")
+		if ok {
+			gid, err := strconv.Atoi(gids)
 			if err != nil {
 				return nil, fmt.Errorf("bad gid: %w", err)
 			}
 			p.User.GID = uint32(gid)
 		}
-		uid, err := strconv.Atoi(uidString)
+		uid, err := strconv.Atoi(uids)
 		if err != nil {
 			return nil, fmt.Errorf("bad uid: %w", err)
 		}