glsl: rename location layout helper
glsl: rename location layout helper

Change name from validate -> apply to more accurately describe what
the function does.

Reviewed-by: Samuel Iglesias Gonsálvez <b753b212f30aed827c3eea2e437609dc37310153@igalia.com>

metora/MesaGLSLCompiler,metora/MesaGLSLCompiler,metora/MesaGLSLCompiler