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

Signed-off-by: Jean-Francois Moine <moinejf@free.fr>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
diff --git a/drivers/media/video/gspca/gspca.c b/drivers/media/video/gspca/gspca.c
index ecf449be..afd99be 100644
--- a/drivers/media/video/gspca/gspca.c
+++ b/drivers/media/video/gspca/gspca.c
@@ -1619,7 +1619,7 @@
 		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;