Simplify link-type checks in soft device supports

src/std/dev/devHistogramSoft.c

@@ -52,20 +52,9 @@ epicsExportAddress(dset,devHistogramSoft);
 
 static long init_record(histogramRecord	*prec)
 {
-    /* histogram.svl must be a CONSTANT or a PV_LINK or a DB_LINK or a CA_LINK*/
-    switch (prec->svl.type) {
-    case (CONSTANT) :
+    if (prec->svl.type == CONSTANT) {
         if(recGblInitConstantLink(&prec->svl,DBF_DOUBLE,&prec->sgnl))
             prec->udf = FALSE;
-	break;
-    case (PV_LINK) :
-    case (DB_LINK) :
-    case (CA_LINK) :
-	break;
-    default :
-	recGblRecordError(S_db_badField,(void *)prec,
-		"devHistogramSoft (init_record) Illegal SVL field");
-	return(S_db_badField);
     }
     return 0;
 }