sockaddr_str: add conversion to,from osmo_sockaddr

Add functions to pass struct osmo_sockaddr to the
osmo_sockaddr_str_{to,from}* API directly.

So far the interface to osmo_sockaddr_str_ is:

  osmo_sockaddr_str_from_sockaddr(&my_sa_str, &my_osa->u.sas);

I'm working a lot with osmo_sockaddr at the moment, and the cumulated
time of forgetting to add 'u.sas' and having another compilation cycle
because of those is justifying this additional API.

Change-Id: I0df84b4bb8cb5d8434b735fa3a38e7f95be43e91
diff --git a/src/core/libosmocore.map b/src/core/libosmocore.map
index fb294ba..c5ab6e3 100644
--- a/src/core/libosmocore.map
+++ b/src/core/libosmocore.map
@@ -400,6 +400,7 @@
 osmo_sockaddr_str_from_sockaddr;
 osmo_sockaddr_str_from_sockaddr_in;
 osmo_sockaddr_str_from_sockaddr_in6;
+osmo_sockaddr_str_from_osa;
 osmo_sockaddr_str_from_str;
 osmo_sockaddr_str_from_str2;
 osmo_sockaddr_str_is_nonzero;
@@ -412,6 +413,7 @@
 osmo_sockaddr_str_to_sockaddr;
 osmo_sockaddr_str_to_sockaddr_in;
 osmo_sockaddr_str_to_sockaddr_in6;
+osmo_sockaddr_str_to_osa;
 osmo_sockaddr_to_octets;
 osmo_sockaddr_to_str;
 osmo_sockaddr_to_str_and_uint;