daemon: Improve error msg for endpoint IP reallocation

Previously, when restoring endpoints, if the reallocation of an IP addr
of an endpoint failed, the error log message didn't include that IP.
E.g.:

    level=warning msg="Unable to restore endpoint, ignoring" endpointID=2930
    error="Failed to re-allocate IP of endpoint: unable to reallocate IPv6
    address: provided IP is not in the valid range. The range of valid IPs
    is f00d::a0c:0:0:0/96" k8sPodName=default/testds-l87pp subsys=daemon

This commit includes IP addr in the error msg for a better troubleshooting.

Signed-off-by: Martynas Pumputis <m@lambda.lt>

daemon/state.go

@@ -326,7 +326,7 @@ func (d *Daemon) allocateIPsLocked(ep *endpoint.Endpoint) error {
 	if option.Config.EnableIPv6 && ep.IPv6 != nil {
 		err = d.ipam.AllocateIP(ep.IPv6.IP(), ep.HumanStringLocked()+" [restored]")
 		if err != nil {
-			return fmt.Errorf("unable to reallocate IPv6 address: %s", err)
+			return fmt.Errorf("unable to reallocate %s IPv6 address: %s", ep.IPv6.IP(), err)
 		}
 
 		defer func() {
@@ -338,7 +338,7 @@ func (d *Daemon) allocateIPsLocked(ep *endpoint.Endpoint) error {
 
 	if option.Config.EnableIPv4 && ep.IPv4 != nil {
 		if err = d.ipam.AllocateIP(ep.IPv4.IP(), ep.HumanStringLocked()+" [restored]"); err != nil {
-			return fmt.Errorf("unable to reallocate IPv4 address: %s", err)
+			return fmt.Errorf("unable to reallocate %s IPv4 address: %s", ep.IPv4.IP(), err)
 		}
 	}