kernel/resource: fix kfree() of bootmem memory again

In the Linux kernel, the following vulnerability has been resolved:

kernel/resource: fix kfree() of bootmem memory again

Since commit ebff7d8f270d ("mem hotunplug: fix kfree() of bootmem memory"), we could get a resource allocated during boot via alloc_resource(). And it's required to release the resource using free_resource(). Howerver, many people use kfree directly which will result in kernel BUG. In order to fix this without fixing every call site, just leak a couple of bytes in such corner case.