i965/vec4/nir: Remove all "this->" snippets
i965/vec4/nir: Remove all "this->" snippets

For consistency, either we have all class members dereferenced, or none.
In this case, very few are so lets get rid of them all.

Reviewed-by: Timothy Arceri <7f85c8176b2576ffafd04ac63cd29ed35ff86cb6@yahoo.com.au>
Reviewed-by: Kenneth Graunke <bd2562f754ec92342f93f61c25d731e290a2ffa8@whitecape.org>

metora/MesaGLSLCompiler,metora/MesaGLSLCompiler,metora/MesaGLSLCompiler