One of the recent change that uses generic types to compact
the symbol table initialization has introduced a bug in 'min'
function implementation, just fixing it here.

TEST= dEQP tests:
dEQP-GLES3.functional.shaders.operator.common_functions.min.lowp_uvec*

Change-Id: I0e3d386c89bc07c3b656ec5029b8ce57f663cf46
Reviewed-on: https://chromium-review.googlesource.com/255369Reviewed-by: Olli Etuaho <oetuaho@nvidia.com>
Tested-by: Olli Etuaho <oetuaho@nvidia.com>
Reviewed-by: Jamie Madill <jmadill@chromium.org>