afs: Fix memory leak in afs_put_sysnames()

Fix afs_put_sysnames() to actually free the specified afs_sysnames
object after its reference count has been decreased to zero and
its contents have been released.

Fixes: 6f8880d8 ("afs: Implement @sys substitution handling")
Signed-off-by: Zhihao Cheng <chengzhihao1@huawei.com>
Signed-off-by: David Howells <dhowells@redhat.com>

fs/afs/proc.c

@@ -567,6 +567,7 @@ void afs_put_sysnames(struct afs_sysnames *sysnames)
 			if (sysnames->subs[i] != afs_init_sysname &&
 			    sysnames->subs[i] != sysnames->blank)
 				kfree(sysnames->subs[i]);
+		kfree(sysnames);
 	}
 }