Increase the size of hdhr_tuner_t.tuner_name

Need to fit 20 characters + \0: HDHR4-2US-xxxxxxxx-y

Change-Id: I435ad740e3481a4d0c133cffe9f8bcafb88ca12d
diff --git a/hdhomerun_tuner.h b/hdhomerun_tuner.h
index 6ac2403..b239f7d 100644
--- a/hdhomerun_tuner.h
+++ b/hdhomerun_tuner.h
@@ -4,7 +4,7 @@
 struct hdhr_tuner_t {
   void *hd;
   int tuner_id;         // unique id in a channel service
-  char tuner_name[20];  // external name used by plugin in a channel service
+  char tuner_name[32];  // external name used by plugin in a channel service
   char name[16];        // internal used by hdhomerun device
   char ip[16];          // device unit ip
   char model[16];       // device model