anolis: net/smc: Introduce sysctl tcp2smc

anolis inclusion
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I76JHC
CVE: NA

Reference: https://gitee.com/anolis/cloud-kernel/commit/834a999fa7461d43ce2bf183ab9de7a5245baf2e



--------------------------------

ANBZ: #5550

This patch adds sysctl 'tcp2smc' to provide a switch for replacing
TCP to SMC-R when new sockets are created in a specific net namespace.

Signed-off-by: Wen Gu <guwen@linux.alibaba.com>
Reviewed-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
Acked-by: Dust Li <dust.li@linux.alibaba.com>
Reviewed-by: Tony Lu <tonylu@linux.alibaba.com>
Link: https://gitee.com/anolis/cloud-kernel/pulls/1754


Signed-off-by: Litao Jiao <jiaolitao@sangfor.com.cn>