swrast: replace __FUNCTION__ with __func__

Consistently just use C99's __func__ everywhere.
The patch was verified with Microsoft Visual studio 2013
redistributable package(RTM version number: 18.0.21005.1)
Next MSVC versions intends to support __func__.
No functional changes.

Acked-by: Matt Turner <mattst88@gmail.com>
Signed-off-by: Marius Predut <marius.predut@intel.com>
5 files changed