net/smc: Do not re-initialize smc hashtables

In the Linux kernel, the following vulnerability has been resolved: net/smc: Do not re-initialize smc hashtables INIT_HLIST_HEAD(&smc_v*_hashinfo.ht) are called after smc_nl_init(), proto_register() and sock_register(). This can lead to smc_v*_hashinfo.ht being reset even though hash entries already exist and are being used, possibly resulting in a corrupted list. Remove unnecessary and dangerous re-initialisation of smc_v*_hashinfo.ht in smc_init(); it is implicitly initialised to zero anyhow. Add HLIST_HEAD_INIT to the definitions for clarity.