glsl: fix an incorrect max_array_access after optimization of ssbo/ubo

glsl: fix an incorrect max_array_access after optimization of ssbo/ubo

This is needed to fix these tests:
piglit.spec.arb_shader_storage_buffer_object.compiler.unused-array-element_frag
piglit.spec.arb_shader_storage_buffer_object.compiler.unused-array-element_comp

Fixes: 8cf1333b "glsl: link uniform block arrays of arrays"
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=109532
Reported-By: Ilia Mirkin <imirkin@alum.mit.edu>
Tested-by: Fritz Koenig <frkoenig@google.com>
Signed-off-by: Andrii Simiklit <andrii.simiklit@globallogic.com>
Reviewed-by: Kristian H. Kristensen <hoegsberg@google.com>