[coverity] compress.cc ensure that we never divide by zero
[coverity] compress.cc ensure that we never divide by zero

Change-Id: I5631455b33f8e09b3a32095e256daf6bde3f11b9
Reviewed-on: http://review.couchbase.org/122359
Tested-by: Build Bot <80754af91bfb6d1073585b046fe0a474ce868509@couchbase.com>
Reviewed-by: Sergey Avseyev <87f6d5e4fd3644c3c20800cde7fd3ad1569370b3@gmail.com>

couchbase/libcouchbase,couchbase/libcouchbase,kojiromike/libcouchbase,kojiromike/libcouchbase,kojiromike/libcouchbase,couchbase/libcouchbase,couchbase/libcouchbase,kojiromike/libcouchbase,couchbase/libcouchbase,couchbase/libcouchbase,couchbase/libcouchbase