net/smc: Fix searching in list of known pnetids in smc_pnet_add_pnetid

pnetid of pi (not newly allocated pe) should be compared

Fixes: e888a2e8 ("net/smc: introduce list of pnetids for Ethernet devices")
Reviewed-by: D. Wythe <alibuda@linux.alibaba.com>
Reviewed-by: Wen Gu <guwen@linux.alibaba.com>
Signed-off-by: Li RongQing <lirongqing@baidu.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Reviewed-by: Gerd Bayer <gbayer@linux.ibm.com>
Link: https://patch.msgid.link/20241014115321.33234-1-lirongqing@baidu.com


Signed-off-by: Jakub Kicinski <kuba@kernel.org>