sdhci-pci: bad error handling in probe function

The goto unmap is too early, we haven't allocated host or done the
request_region().

Found by smatch (http://repo.or.cz/w/smatch.git).

[ Second error path fix by Pierre Ossman ]

Signed-off-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: Pierre Ossman <pierre@ossman.eu>