PCI: hotplug: pci_hotplug_core whitespace fix

Remove superfluous space.

Signed-off-by: Alex Chiang <achiang@hp.com>
Signed-off-by: Matthew Wilcox <matthew@wil.cx>
Signed-off-by: Kristen Carlson Accardi <kristen.c.accardi@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>