ide-cd: remove needless zeroing of 'info' fields from ide_cdrom_setup()

ide_cd_probe() zeroes 'info' prior to calling ide_cdrom_setup() so there
is no need to explicitly zero 'info' fields in the latter function.

Ditto for fields of CDROM_STATE_FLAGS(), CDROM_CONFIG_FLAGS() and 'cdi'
(all are embedded in 'info').

Acked-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>