__FUNCTION__ is MSVC only, in Linux, it is __func__. Lv Zheng.
As noted by Christoph Hellwig: "__func__ is in C99 and never.
__FUNCTION__ is an old extension supported by various compilers."
In ACPICA, this is achieved by string replacement in release script and
this patch contains the source code difference between the Linux upstream
and ACPICA that is caused by the back porting.