provider/google: Fix google_compute_backend_service max_utilization b…

…ackend attribute

Fixes issue #4985 by correcting copy/paste error
N.B. There is still no test coverage for this issue.

builtin/providers/google/resource_compute_backend_service.go

@@ -300,7 +300,7 @@ func expandBackends(configured []interface{}) []*compute.Backend {
 		if v, ok := data["max_rate_per_instance"]; ok {
 			b.MaxRatePerInstance = v.(float64)
 		}
-		if v, ok := data["max_rate_per_instance"]; ok {
+		if v, ok := data["max_utilization"]; ok {
 			b.MaxUtilization = v.(float64)
 		}