fix memleak with storedur and invalid requirements
fix memleak with storedur and invalid requirements

We didn't free the context on error

Change-Id: Ibdf36ac71ed045c4f0550c539e682c88ff38896d
Reviewed-on: http://review.couchbase.org/56872
Reviewed-by: Subhashni Balakrishnan <7129c8e37b832c7bd362ff375532d24b98ef5162@gmail.com>
Tested-by: Mark Nunberg <dab05a0fe859c5cb93882b2a75a0d613501b07be@couchbase.com>

mody/libcouchbase,couchbase/libcouchbase,kojiromike/libcouchbase,avsej/libcouchbase,couchbase/libcouchbase,mody/libcouchbase,couchbase/libcouchbase,avsej/libcouchbase,avsej/libcouchbase,couchbase/libcouchbase,kojiromike/libcouchbase,avsej/libcouchbase,couchbase/libcouchbase,mody/libcouchbase,avsej/libcouchbase,kojiromike/libcouchbase,kojiromike/libcouchbase,avsej/libcouchbase,avsej/libcouchbase,mody/libcouchbase,couchbase/libcouchbase,couchbase/libcouchbase