Restrict newcat_set_cmd_validate BS to only rigs with get_vfo and set_vfo

https://github.com/Hamlib/Hamlib/issues/510

rigs/yaesu/newcat.c

@@ -822,7 +822,8 @@ int newcat_set_freq(RIG *rig, vfo_t vfo, freq_t freq)
     if (newcat_valid_command(rig, "BS") && changing
             // remove the split check here -- hopefully works OK
             //&& !rig->state.cache.split
-            && !is_ft891) // 891 does not remember bandwidth so don't do this
+            && !is_ft891 // 891 does not remember bandwidth so don't do this
+            && rig->caps->get_vfo!=NULL && rig->caps->set_vfo!=NULL)  // gotta' have get_vfo too
     {
         snprintf(priv->cmd_str, sizeof(priv->cmd_str), "BS%02d%c",
                  newcat_band_index(freq), cat_term);
@@ -874,7 +875,10 @@ int newcat_set_freq(RIG *rig, vfo_t vfo, freq_t freq)
                 err = rig_set_vfo(rig, vfotmp == RIG_VFO_A ? RIG_VFO_A : RIG_VFO_B);
             }
 
-            if (err != RIG_OK) { return err; }
+            if (err != RIG_OK) { 
+                rig_debug(RIG_DEBUG_ERR, "%s: rig_set_vfo failed: %s\n", __func__, rigerror(err));
+                return err; 
+            }
 
             // after band select re-read things -- may not have to change anything
             freq_t tmp_freqA, tmp_freqB;

rigs/yaesu/newcat.h

@@ -50,7 +50,7 @@
 typedef char ncboolean;
 
 /* shared function version */
-#define NEWCAT_VER "20210115"
+#define NEWCAT_VER "20210116"
 
 /* Hopefully large enough for future use, 128 chars plus '\0' */
 #define NEWCAT_DATA_LEN                 129