ipcache: Avoid refcnt underflow and print error when attempted
ipcache: Avoid refcnt underflow and print error when attempted

An asymmetric call to release() would currently result in an underflow of the
reference counter which permanently damage the reference count state. Avoid
the underflow and add an error log.

Signed-off-by: Thomas Graf <5f50a84c1fa3bcff146405017f36aec1a10a9e38@cilium.io>

tklauser/cilium,cilium/cilium,scanf/cilium,scanf/cilium,cilium/cilium,michi-covalent/cilium,scanf/cilium,cilium-team/cilium,tklauser/cilium,cilium-team/cilium,scanf/cilium,tklauser/cilium,tgraf/cilium,scanf/cilium,michi-covalent/cilium,michi-covalent/cilium,cilium/cilium,tgraf/cilium,tklauser/cilium,michi-covalent/cilium,cilium/cilium,tklauser/cilium,tgraf/cilium,tgraf/cilium,scanf/cilium,tgraf/cilium,scanf/cilium,cilium/cilium,michi-covalent/cilium,tgraf/cilium