remove code dup: add msc_mgcp_try_call_assignment()

Various places in the code check a flag whether assignment was started and
launch it. To fix incoming-call-during-ongoing-call, I will tweak that logic.
To be able to do that only in one place, remove code dup.

Cosmetic preparation for I1f8746e7babfcd3028a4d2c0ba260c608c686c76 and
I0ba216b737909e92080a722db26e3577726c63cb/

Depends: I11b182a03f5ecb6df7cd8f260757d3626c8e945d (libosmocore: LOGPFSMSL)
Change-Id: I11c0b7dc3f1a747028629b48e522bb3b864884ba
diff --git a/tests/msc_vlr/Makefile.am b/tests/msc_vlr/Makefile.am
index bdb8f44..8a5e719 100644
--- a/tests/msc_vlr/Makefile.am
+++ b/tests/msc_vlr/Makefile.am
@@ -32,7 +32,7 @@
 	-Wl,--wrap=gsm340_gen_scts \
 	-Wl,--wrap=osmo_get_rand_id \
 	-Wl,--wrap=msc_mgcp_call_release \
-	-Wl,--wrap=msc_mgcp_call_assignment \
+	-Wl,--wrap=msc_mgcp_try_call_assignment \
 	-Wl,--wrap=a_iface_tx_cipher_mode \
 	-Wl,--wrap=ranap_iu_tx_sec_mode_cmd \
 	-Wl,--wrap=osmo_sccp_tx_data_msg \