cleanup: resolve nlreturn linter issues

nlreturn linter requires a new line before return
and branch statements except when the return is alone
inside a statement group (such as an if statement) to
increase code clarity. This commit addresses such issues.

Updates: #1586

Signed-off-by: Rakshith R <rar@redhat.com>

e2e/upgrade.go

@@ -22,6 +22,7 @@ func upgradeCSI(version string) error {
 	if err != nil {
 		return fmt.Errorf("unable to switch directory : %w", err)
 	}
+
 	return nil
 }
 
@@ -38,5 +39,6 @@ func upgradeAndDeployCSI(version, testtype string) error {
 	default:
 		return errors.New("incorrect test type, can be cephfs/rbd")
 	}
+
 	return nil
 }