msgb: add inline msgb_queue_free()

Related: Iaad35f03e3bdfabf3ba82b16e563c0a5d1f03639 (libosmo-netif)
Change-Id: Ia291832ca445d4071f0ed9a01730d945ff691cf7
diff --git a/TODO-RELEASE b/TODO-RELEASE
index fb0bfea..99865c6 100644
--- a/TODO-RELEASE
+++ b/TODO-RELEASE
@@ -7,3 +7,4 @@
 # If any interfaces have been added since the last public release: c:r:a + 1.
 # If any interfaces have been removed or changed since the last public release: c:r:0.
 #library	what			description / commit summary line
+core		msgb_queue_free()	add inline func to msgb.h