pciehp: fixes typo in dbg_ctrl() in pciehp_hpc.c

Fixup a typo in dbg_ctrl(); it was fetching SLOTSTATUS twice.

Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Kristen Carlson Accardi <kristen.c.accardi@intel.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>