cb468f libz: patch: address inconsisten visibility definition of z_errmsg.

1 file Authored by midipix 5 years ago, Committed by Lucio Andrés Illanes Albornoz 5 years ago,
    libz: patch: address inconsisten visibility definition of z_errmsg.
    
    Signed-off-by: Lucio Andrés Illanes Albornoz <lucio@lucioillanes.de>