glsl: remove remaining tabs from ast_array_index.cpp
glsl: remove remaining tabs from ast_array_index.cpp

Acked-by: Dave Airlie <f2295d84e358395675bc8031be58672073ae065e@redhat.com>

metora/MesaGLSLCompiler,metora/MesaGLSLCompiler,metora/MesaGLSLCompiler