PCBC-319: Pass doc during durability_callback to correct segfault.
PCBC-319: Pass doc during durability_callback to correct segfault.

Previously NULL was being passed in error causing an exception to occur
when a durability operation failed.

JordyMoos/php-couchbase,JordyMoos/php-couchbase,nkovacs/php-couchbase,brett19/php-couchbase,couchbase/php-couchbase,nkovacs/php-couchbase,JordyMoos/php-couchbase,couchbaselabs/php-couchbase,couchbase/php-couchbase,brett19/php-couchbase,nkovacs/php-couchbase,couchbase/php-couchbase,brett19/php-couchbase,couchbaselabs/php-couchbase,brett19/php-couchbase,couchbaselabs/php-couchbase,couchbase/php-couchbase,couchbaselabs/php-couchbase