ide-cd: signedness warning fix again

One of the legit warnings 'make W=3 drivers/ide/ide-cd.c'
generates is:
drivers/ide/ide-cd.c: In function ide_cd_do_request
drivers/ide/ide-cd.c:828:2: warning: conversion to int from \
unsigned int may change the sign of the result
drivers/ide/ide-cd.c:833:2: warning: conversion to int from \
unsigned int may change the sign of the result

nsectors is declared int, should be unsigned int.

blk_rq_sectors() returns unsigned int, and ide_complete_rq
expects unsigned int as well.  Fixes both warnings.

Signed-off-by: Connor Hansen <cmdkhh@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>