tests/msc_vlr: fix expected SS message names

Since the I697639d8469e5dda617b27995c4a92e1f0c0bead, call
independent SS messages are also supported by
gsm48_pdisc_msgtype_name().

So, instead of 'NCSS:0x3b' it will return 'GSM0480_MTYPE_REGISTER'.
Let's correct the expected message names.

Change-Id: If9e854ee84882d104cf2ffaceb3862fda6862f19
6 files changed