pata_legacy: fix CONFIG_PATA_WINBOND_VLB_MODULE test

pata_legacy is incorrectly testing PATA_WINBOND_VLB_MODULE instead of
CONFIG_PATA_WINBOND_VLB_MODULE.  Fix it.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: "Robert P. J. Day" <rpjday@crashcourse.ca>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>