Fix OneDefinitionRule Asan violation in tests and osmo-hnbgw

With new gcc 10.1.0, tests failed at runtime when built with ASAN
enabled, since some global variables where defined multiple times.
See OS#4556 for a sample Asan error.

Fixes: OS#4556
Change-Id: I12a667ea8a9f16404c13c9218b246d2e3acfe3e8
diff --git a/src/tests/test-helpers.c b/src/tests/test-helpers.c
index aafe815..cfe2140 100644
--- a/src/tests/test-helpers.c
+++ b/src/tests/test-helpers.c
@@ -32,7 +32,6 @@
 
 #include <osmocom/ranap/RANAP_LAI.h>
 
-int asn1_xer_print = 0;
 extern void *talloc_asn1_ctx;
 
 /* use odd number of digits */
@@ -207,6 +206,8 @@
 
 int main(int argc, char **argv)
 {
+	asn1_xer_print = 0;
+
 	test_common_init();
 
 	test_iu_helpers();