rename oap.h to oap_client.h

Related: OS#1592
Change-Id: I05bd65ff81b0f70f68217b2e0a9466e160bdbdec
diff --git a/openbsc/tests/oap/oap_test.c b/openbsc/tests/oap/oap_test.c
index a6f54f6..adac911 100644
--- a/openbsc/tests/oap/oap_test.c
+++ b/openbsc/tests/oap/oap_test.c
@@ -22,7 +22,7 @@
 #include <osmocom/gsm/oap.h>
 
 #include <openbsc/debug.h>
-#include <openbsc/oap.h>
+#include <openbsc/oap_client.h>
 
 #include <stdio.h>
 #include <string.h>