scsi: target: core: Fix error path in target_setup_session()

In the error exits in target_setup_session(), if a branch is taken to
free_sess: transport_free_session() may call to target_free_cmd_counter()
and then fall through to call target_free_cmd_counter() a second time.
This can, and does, sometimes cause seg faults since the data field in
cmd_cnt->refcnt has been freed in the first call.

Fix this problem by simply returning after the call to
transport_free_session(). The second call is redundant for those cases.

Fixes: 4edba7e4 ("scsi: target: Move cmd counter allocation")
Signed-off-by: Bob Pearson <rpearsonhpe@gmail.com>
Link: https://lore.kernel.org/r/20230613144259.12890-1-rpearsonhpe@gmail.comReviewed-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/target/target_core_transport.c

@@ -504,6 +504,8 @@ target_setup_session(struct se_portal_group *tpg,
 
 free_sess:
 	transport_free_session(sess);
+	return ERR_PTR(rc);
+
 free_cnt:
 	target_free_cmd_counter(cmd_cnt);
 	return ERR_PTR(rc);