Maguire's17552 Dallas Parkway972-818-0068When a restaurateur decides to back a second (or third) venture, does the original suffer? Yeah, sometimes.But Mark Maguire is an old hand at openings, what with the former M Grill and current Rise No. 1 and Maximo to his credit. Still, the North Dallas location--Maguire's--continues to plug along, unfazed by whatever developments distract its ownership.You have to give Maguire a nod on this. Too many restaurateurs forsake the old for the lure of new and