mesa: remove an extern "C" wrapper in shader_query.cpp
mesa: remove an extern "C" wrapper in shader_query.cpp

The shaderapi.h header already has the extern "C" wrapper.

Reviewed-by: Matt Turner <789b315743a28dd066a4ba1459c35951c291d8a6@gmail.com>

metora/MesaGLSLCompiler,metora/MesaGLSLCompiler,metora/MesaGLSLCompiler