Check for N1QL errors even on non-200 status codes.

At some point, N1QL was updated to return a 200 status code
even in the case of an error occuring.  The previous logic
caused these errors to be ignored, and an empty result set
to be returned instead.

Change-Id: Id70e89d0c25a460ac940c50e497d3b2a9c6ecbd1
Reviewed-on: http://review.couchbase.org/63114
Reviewed-by: Mark Nunberg <mark.nunberg@couchbase.com>
Tested-by: Brett Lawson <brett19@gmail.com>

cluster_query.go

@@ -143,11 +143,11 @@ func (c *Cluster) executeN1qlQuery(n1qlEp string, opts map[string]interface{}, c
 
 	resp.Body.Close()
 
-	if resp.StatusCode != 200 {
-		if len(n1qlResp.Errors) > 0 {
-			return nil, (*n1qlMultiError)(&n1qlResp.Errors)
-		}
+	if len(n1qlResp.Errors) > 0 {
+		return nil, (*n1qlMultiError)(&n1qlResp.Errors)
+	}
 
+	if resp.StatusCode != 200 {
 		return nil, &viewError{
 			Message: "HTTP Error",
 			Reason:  fmt.Sprintf("Status code was %d.", resp.StatusCode),