ni52: kill the second argument of check586(), get rid of bogus pointer

Passing ISA bus address explicitly cast to char * only to cast it back to
unsigned long is dumb; so's passing it at all when it's always dev->mem_start...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Jeff Garzik <jeff@garzik.org>