oap_client: Rename symbols with osmo_ prefix

As we're moving this to a common/shared library now, we need to use
the osmo_ namespace prefix for symbol names, struct/type names and
constants.

Change-Id: Ie36729996abd30b84d1c30a09f62ebc6a9794950
diff --git a/src/gsm/libosmogsm.map b/src/gsm/libosmogsm.map
index 6eb60cc..bc9ed52 100644
--- a/src/gsm/libosmogsm.map
+++ b/src/gsm/libosmogsm.map
@@ -493,10 +493,10 @@
 osmo_mncc_names;
 _osmo_mncc_log;
 
-oap_client_encoded;
-oap_client_handle;
-oap_client_init;
-oap_client_register;
+osmo_oap_client_encoded;
+osmo_oap_client_handle;
+osmo_oap_client_init;
+osmo_oap_client_register;
 
 local: *;
 };