V4L/DVB (13387): gspca - main: Fix a compilation warning.

Signed-off-by: NJean-Francois Moine <moinejf@free.fr>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/video/gspca/gspca.c

@@ -1619,7 +1619,7 @@ static int dev_mmap(struct file *file, struct vm_area_struct *vma)
 		size -= PAGE_SIZE;
 	}
 
-	vma->vm_ops = &gspca_vm_ops;
+	vma->vm_ops = (struct vm_operations_struct *) &gspca_vm_ops;
 	vma->vm_private_data = frame;
 	gspca_vm_open(vma);
 	ret = 0;