Dear Swift,
The gsmmap branch that you are using was created to allow users to submit their own traffic to gsmmap.org and it's not meant to be used as a mass interception tool. If you use ccch_scan _and_ specify your ARFCN _and_ specify your TMSI _and_ your network does not use encryption, then you will probably be able to see your SMS in wireshark. Please note that the TMSI may be re-allocated by the network at any time.
To make testing easier I suggest you to use a second Osmocom phone running the official mobile application/firmware and set the "stick" option in the configuration, so the ARFCN will not change.
Cheers,
LM