smc: preserve const qualifier in smc_sk()

JIRA: https://issues.redhat.com/browse/RHEL-73484

commit 407db47
Author: Eric Dumazet <[email protected]>
Date:   Fri Mar 17 15:55:36 2023 +0000

    smc: preserve const qualifier in smc_sk()

    We can change smc_sk() to propagate its argument const qualifier,
    thanks to container_of_const().

    Signed-off-by: Eric Dumazet <[email protected]>
    Cc: Karsten Graul <[email protected]>
    Cc: Wenjia Zhang <[email protected]>
    Cc: Jan Karcher <[email protected]>
    Reviewed-by: Simon Horman <[email protected]>
    Reviewed-by: Wenjia Zhang <[email protected]>
    Signed-off-by: David S. Miller <[email protected]>

Signed-off-by: Mete Durlu <[email protected]>

Author: Mete Durlu

net/smc/smc.h

@@ -283,10 +283,7 @@ struct smc_sock {				/* smc sock container */
 						 * */
 };
 
-static inline struct smc_sock *smc_sk(const struct sock *sk)
-{
-	return (struct smc_sock *)sk;
-}
+#define smc_sk(ptr) container_of_const(ptr, struct smc_sock, sk)
 
 static inline void smc_init_saved_callbacks(struct smc_sock *smc)
 {