selinux: simplify avtab_insert_node() prototype

__hashtab_insert() in hashtab.h has a cleaner interface that allows the
caller to specify the chain node location that the new node is being
inserted into so that it can update the node that currently occupies it.
Signed-off-by: Jacob Satterfield <jsatterfield.linux@gmail.com>
Reviewed-by: Stephen Smalley <stephen.smalley.work@gmail.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

security/selinux/ss/avtab.c

@@ -67,8 +67,7 @@ static inline u32 avtab_hash(const struct avtab_key *keyp, u32 mask)
 }
 
 static struct avtab_node*
-avtab_insert_node(struct avtab *h, u32 hvalue,
-		  struct avtab_node *prev,
+avtab_insert_node(struct avtab *h, struct avtab_node **dst,
 		  const struct avtab_key *key, const struct avtab_datum *datum)
 {
 	struct avtab_node *newnode;
@@ -90,15 +89,8 @@ avtab_insert_node(struct avtab *h, u32 hvalue,
 		newnode->datum.u.data = datum->u.data;
 	}
 
-	if (prev) {
-		newnode->next = prev->next;
-		prev->next = newnode;
-	} else {
-		struct avtab_node **n = &h->htable[hvalue];
-
-		newnode->next = *n;
-		*n = newnode;
-	}
+	newnode->next = *dst;
+	*dst = newnode;
 
 	h->nel++;
 	return newnode;
@@ -138,7 +130,8 @@ static int avtab_insert(struct avtab *h, const struct avtab_key *key,
 			break;
 	}
 
-	newnode = avtab_insert_node(h, hvalue, prev, key, datum);
+	newnode = avtab_insert_node(h, prev ? &prev->next : &h->htable[hvalue],
+				    key, datum);
 	if (!newnode)
 		return -ENOMEM;
 
@@ -178,7 +171,8 @@ struct avtab_node *avtab_insert_nonunique(struct avtab *h,
 		    key->target_class < cur->key.target_class)
 			break;
 	}
-	return avtab_insert_node(h, hvalue, prev, key, datum);
+	return avtab_insert_node(h, prev ? &prev->next : &h->htable[hvalue],
+				 key, datum);
 }
 
 /* This search function returns a node pointer, and can be used in