Fix integer truncation warnings from Clang
Fix integer truncation warnings from Clang

ssize_t assignment to couchstore_error_t requires explicit cast
since it's throwing away the upper half of a 64-bit value.

Change-Id: If4456dcb1a8fd34234bde433d30d2441c6dcb90d
Reviewed-on: http://review.couchbase.org/19179
Tested-by: Aaron Miller <41fcc51335f382e0855796cc35dd33f571f2d8f7@ninjawhale.com>
Reviewed-by: Aaron Miller <41fcc51335f382e0855796cc35dd33f571f2d8f7@ninjawhale.com>

abhinavdangeti/couchstore,hsharsha/couchstore,jimwwalker/couchstore,couchbaselabs/couchstore,jimwwalker/couchstore,couchbaselabs/couchstore-specials,abhinavdangeti/couchstore,t3rm1n4l/couchstore,hsharsha/couchstore,vmx/couchstore,vmx/couchstore,couchbaselabs/couchstore-specials,couchbaselabs/couchstore-specials,couchbaselabs/couchstore-specials,hsharsha/couchstore,couchbaselabs/couchstore,jimwwalker/couchstore,couchbaselabs/couchstore,vmx/couchstore,t3rm1n4l/couchstore,abhinavdangeti/couchstore,hsharsha/couchstore,couchbaselabs/couchstore-specials,t3rm1n4l/couchstore