tgsi: fixup the string of VS_WINDOW_SPACE_POSITION
tgsi: fixup the string of VS_WINDOW_SPACE_POSITION

Tested-by: Nick Sarnie <d07c1d7cf44b065e41eacfb61ed82c2729dd598f@gmail.com>

metora/MesaGLSLCompiler,metora/MesaGLSLCompiler,metora/MesaGLSLCompiler