Corrected segfault when using unwriteable cache directory.
Corrected segfault when using unwriteable cache directory.

We were not exiting the control flow properly for a
certain type of error.

Change-Id: I66775e0d0cd10ec968dbc0f6a6fc94f943d9ee0e
Reviewed-on: http://review.couchbase.org/34644
Reviewed-by: Mark Nunberg <e7d42768707bf23038325b0b68d4b577e5f6064a@haskalah.org>
Tested-by: Brett Lawson <c8c4369773d7d7226e031f0c4af62e3f38a08510@gmail.com>

couchbase/php-ext-couchbase,couchbase/php-ext-couchbase,couchbase/php-ext-couchbase,couchbase/php-ext-couchbase,couchbase/php-ext-couchbase