BACKPORT: exfat: fix overflow for large capacity partition

Using int type for sector index, there will be overflow in a large
capacity partition.

For example, if storage with sector size of 512 bytes and partition
capacity is larger than 2TB, there will be overflow.

Bug: 254441685
Fixes: 1b613838 ("exfat: reduce block requests when zeroing a cluster")
Cc: stable@vger.kernel.org # v5.19+
Signed-off-by: Yuezhang Mo <Yuezhang.Mo@sony.com>
Reviewed-by: Andy Wu <Andy.Wu@sony.com>
Reviewed-by: Aoyama Wataru <wataru.aoyama@sony.com>
Acked-by: Sungjong Seo <sj1557.seo@samsung.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
(cherry picked from commit 2e9ceb67)
Signed-off-by: Lee Jones <joneslee@google.com>
Change-Id: I0ebd4d6d3ac9e0e5b50f58a62e5b49ef4959b3e3