clairctl: Scan the pointer to the pointer of the bool

I believe that even though ok is a *bool type, we still need to pass
it's address to Scan() otherwise it's akin to ok := bool; Scan(&ok),
which I believe only supports binary values and not nullable bools.

Signed-off-by: crozzy <joseph.crosland@gmail.com>

cmd/clairctl/admin.go

@@ -120,7 +120,7 @@ func adminPre470(c *cli.Context) error {
 		const mkindex = `CREATE INDEX CONCURRENTLY IF NOT EXISTS idx_manifest_index_manifest_id ON manifest_index(manifest_id);`
 		const reindex = `REINDEX INDEX CONCURRENTLY idx_manifest_index_manifest_id;`
 		var ok *bool
-		if err := conn.QueryRow(ctx, checkindex).Scan(ok); err != nil {
+		if err := conn.QueryRow(ctx, checkindex).Scan(&ok); err != nil {
 			if !errors.Is(err, pgx.ErrNoRows) {
 				zlog.Info(ctx).
 					AnErr("index_check", err).