Current acpiphp does not free acpi_device structs when the
PCI devices are removed. When the PCI device is added,
acpi_bus_add() fails because acpi_device struct has already
exists. So, _PRT method does not evaluate.

This patch fixes this issue.
Signed-off-by: MUNEDA Takahiro <muneda.takahiro@jp.fujitsu.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>