Revert "lapdm: Append RSL_IE_OSMO_ABS_FRAME_NUMBER to RSLms msgs towards upper layers"

This reverts commit d981794113efef3cc1195cde82043c5c66937b11.

osmo-bts is forwarding the msgbs as they come from lapdm to the RSL on
the wire, which means we end up sending the osmocom-specific IEs on the
wire, something which was not envisioned when adding this IE.

Change-Id: I0ab0d5b545b4862e72eb1842edd07ca2e4955311
Related: OS#6142
diff --git a/tests/lapd/lapd_test.c b/tests/lapd/lapd_test.c
index bae73c2..2f2a7f4 100644
--- a/tests/lapd/lapd_test.c
+++ b/tests/lapd/lapd_test.c
@@ -359,7 +359,7 @@
 		struct abis_rsl_rll_hdr hdr;
 
 		printf("MS: Verifying incoming primitive.\n");
-		OSMO_ASSERT(msg->len >= sizeof(struct abis_rsl_rll_hdr));
+		OSMO_ASSERT(msg->len == sizeof(struct abis_rsl_rll_hdr));
 
 		/* verify the header */
 		memset(&hdr, 0, sizeof(hdr));