When acpiphp_enable_slot() is failed, acpiphp does not change
the slot->flags. Therefore, when user tries to read power
status, acpiphp_get_power_status() returns the enable status
whether the slot is not really enabled.

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