mtd: nand: fix integer widening problems

chip->pagebuf is a 32-bit type (int), so the shift will only be applied
as 32-bit. Fix this for 64-bit safety.

Caught by Coverity.
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>

drivers/mtd/nand/nand_base.c

@@ -2409,8 +2409,8 @@ static int nand_do_write_ops(struct mtd_info *mtd, loff_t to,
 	blockmask = (1 << (chip->phys_erase_shift - chip->page_shift)) - 1;
 
 	/* Invalidate the page cache, when we write to the cached page */
-	if (to <= (chip->pagebuf << chip->page_shift) &&
-	    (chip->pagebuf << chip->page_shift) < (to + ops->len))
+	if (to <= ((loff_t)chip->pagebuf << chip->page_shift) &&
+	    ((loff_t)chip->pagebuf << chip->page_shift) < (to + ops->len))
 		chip->pagebuf = -1;
 
 	/* Don't allow multipage oob writes with offset */