Fixes unsafe get on port cache

Get on port cache was returning the actual object in the cache instead
of a copy.

Signed-off-by: Tim Rozet <trozet@redhat.com>

go-controller/pkg/ovn/port_cache.go

@@ -37,7 +37,8 @@ func (c *portCache) get(logicalPort string) (*lpInfo, error) {
 	c.RLock()
 	defer c.RUnlock()
 	if info, ok := c.cache[logicalPort]; ok {
-		return info, nil
+		x := *info
+		return &x, nil
 	}
 	return nil, fmt.Errorf("logical port %s not found in cache", logicalPort)
 }