isapnp: remove pointless check of 'type' against 0 in isapnp_read_tag()
In drivers/pnp/isapnp/core.c::isapnp_read_tag() there is a test of 'type'
being == 0 a bit down in the function. That test doesn't make any sense.
If 'type' could indeed be NULL, then the test happens way too late as we'd
already have tried to dereference the pointer earlier and looking at the
callers it also turns out that there is no way type can ever actually be
NULL.
So the test is completely pointless and should just be removed.