!826 [OLK-5.10] net/smc: mutex lock optimize

Merge Pull Request from: @giree2 
 
1. replace llc_conf_mutex with rw_semaphore
2. use read semaphores to reduce unnecessary blocking in smc_buf_create() & smcr_buf_unuse()
3. replace mutex rmbs_lock and sndbufs_lock with rw_semaphore
4. modify llc_conf_mutex variable to llc_conf_lock. 
 
Link:https://gitee.com/openeuler/kernel/pulls/826

 

Reviewed-by: Jialin Zhang <zhangjialin11@huawei.com>
Signed-off-by: Jialin Zhang <zhangjialin11@huawei.com>