block: do not call sector_div() with a 64-bit divisor

block: do not call sector_div() with a 64-bit divisor

do_div() (called by sector_div() if CONFIG_LBDAF=y) is meant for divisions
of 64-bit number by 32-bit numbers.  Passing 64-bit divisor types caused
issues in the past on 32-bit platforms, cfr.  commit ea077b1b96e073ea
("m68k: Truncate base in do_div()").

As queue_limits.max_discard_sectors and .discard_granularity are unsigned
int, max_discard_sectors and granularity should be unsigned int.  As
bdev_discard_alignment() returns int, alignment should be int.  Now 2
calls to sector_div() can be replaced by 32-bit arithmetic:

  - The 64-bit modulo operation can become a 32-bit modulo operation,
  - The 64-bit division and multiplication can be replaced by a 32-bit
    modulo operation and a subtraction.

Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>