Workaround: JackClient: Fix printf NULL issue

vsnprintf implementation on QNX can not handle NULL string parameter and
will interrupt, This is a workaround for the same

Change-Id: I18c57ec4b596336cea6f3061caf49c0b33afe198
Signed-off-by: Laxmi Devi <Laxmi.Devi@in.bosch.com>

common/JackClient.cpp

@@ -34,6 +34,15 @@ Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 
 using namespace std;
 
+#ifdef __QNXNTO__
+void __attribute__((constructor)) init_output_for_percent_s_NULL_for_clients();
+void init_output_for_percent_s_NULL_for_clients()
+{
+    extern const char *output_for_percent_s_NULL;
+    output_for_percent_s_NULL = "(null)";
+}
+#endif
+
 namespace Jack
 {