There are three positive return codes from inflate

 #define Z_OK            0
 #define Z_STREAM_END    1
 #define Z_NEED_DICT     2

and we don't support dictionaries, so a Z_NEED_DICT return
creates an infinite loop

Change-Id: Iafb1da594962b3cb456a3223cc6d4122791718c5
(cherry picked from commit 047830de46fc40629dc9bdf1e8b9f427b6648c36)
Reviewed-on: https://gerrit.libreoffice.org/12366
Reviewed-by: Michael Stahl <mstahl@redhat.com>
Tested-by: Michael Stahl <mstahl@redhat.com>