pciehp: remove trailing whitespace from pciehp_ctrl.c

Remove trailing whitespaces from pciehp_ctrl.c.
Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Kristen Carlson Accardi <kristen.c.accardi@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>