[PATCH] acpiphp: fix acpi_path_name

I encountered the problem that the insmod of the acpiphp
fails because of the mis-freeing of the memory.

I tested this patch on my tiger4 box.

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