CVE-2024-44996 vsock: fix recursive ->recvmsg calls

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

vsock: fix recursive ->recvmsg calls

After a vsock socket has been added to a BPF sockmap, its prot->recvmsg
has been replaced with vsock_bpf_recvmsg(). Thus the following
recursiion could happen:

vsock_bpf_recvmsg()
-> __vsock_recvmsg()
-> vsock_connectible_recvmsg()
-> prot->recvmsg()
-> vsock_bpf_recvmsg() again

We need to fix it by calling the original ->recvmsg() without any BPF
sockmap logic in __vsock_recvmsg().