Guests at the celeb-packed Chateau Marmont ducked for cover Saturday as parts of the roof began falling into the outdoor dining area as high winds swept through the area. Diners — including “Borat” star Sacha Baron Cohen — were stunned when a slate and a huge piece of gutter plunged toward them during brunch service at the ritzy Los Angeles hotel. One woman suddenly jumped up and held the gutter in place to stop it falling on her female companion, while others whipped their heads around after