Refactor shm_str_resize() into shm_str_extend()

This hints better at what the function actually does (i.e. it will not
shrink your buffers)

modules/fraud_detection/fraud_detection.c

@@ -346,7 +346,7 @@ static int check_fraud(struct sip_msg *msg, char *_user, char *_number, char *_p
 		++se->stats.seq_calls;
 	}
 	else {
-		if (shm_str_resize(&se->stats.last_called_prefix, matched_len) != 0) {
+		if (shm_str_extend(&se->stats.last_called_prefix, matched_len) != 0) {
 			LM_ERR("oom\n");
 			return rc_error;
 		}

modules/usrloc/kv_store.c

@@ -74,7 +74,7 @@ int_str_t *kv_put(map_t _store, const str* _key, const int_str_t* _val)
 			new_val->is_str = 1;
 		}
 
-		if (shm_str_resize(&new_val->s, _val->s.len + 1) != 0) {
+		if (shm_str_extend(&new_val->s, _val->s.len + 1) != 0) {
 			LM_ERR("oom\n");
 			return NULL;
 		}

ut.h

@@ -677,8 +677,12 @@ static inline char *shm_strdup(const char *str)
 	return rval;
 }
 
-/* Extend the given buffer only if needed */
-static inline int shm_str_resize(str *in, int size)
+/*
+ * Ensure the given (str *) points to an SHM buffer of at least "size" bytes
+ *
+ * Return: 0 on success, -1 on failure
+ */
+static inline int shm_str_extend(str *in, int size)
 {
 	char *p;