seqRecord: fix upper display limit of the DLYn fields

get_graphic_double() assigns lower_disp_limit twice and never writes
upper_disp_limit, so a DBR_GR_DOUBLE read of any DLYn field reports
the inverted range lower=10, upper=0.  The second assignment was
evidently meant for the upper limit; the 0 in the upper slot is the
zeroed buffer dbAccess.c hands to the RSET, not a chosen value.

Both assignments date from commit 27e80be2e5 which introduced the
DLYn limits, so every release since 3.14.11 reports the inverted
range over both CA (DBR_GR/CTRL) and PVA (display.limitLow/High).

Extend seqTest with a DBR_GR_DOUBLE read of DLY0; the new cases
fail with lower=10, upper=0 before this fix.

modules/database/src/std/rec/seqRecord.c

@@ -327,7 +327,7 @@ static long get_graphic_double(DBADDR *paddr, struct dbr_grDouble *pgd)
         switch (fieldOffset & 3) {
         case 0: /* DLYn */
             pgd->lower_disp_limit = 0.0;
-            pgd->lower_disp_limit = 10.0;
+            pgd->upper_disp_limit = 10.0;
             return 0;
         case 2: /* DOn */
             dbGetGraphicLimits(get_dol(prec, fieldOffset),

modules/database/test/std/rec/seqTest.c

@@ -13,6 +13,27 @@
 
 void recTestIoc_registerRecordDeviceDriver(struct dbBase *);
 
+/*
+ * The DLYn fields advertise a display range of 0 to 10 seconds
+ * */
+static
+void testSeqDlyLimits(void){
+    DBADDR addr;
+    struct {
+        DBRgrDouble
+        epicsFloat64 value;
+    } buf;
+    long options = DBR_GR_DOUBLE;
+    long nRequest = 1;
+
+    testOk1(!dbNameToAddr("seq0.DLY0", &addr));
+    testOk1(!dbGetField(&addr, DBR_DOUBLE, &buf, &options, &nRequest, NULL));
+    testOk(buf.lower_disp_limit == 0.0,
+        "DLY0 lower_disp_limit (%g) == 0", buf.lower_disp_limit);
+    testOk(buf.upper_disp_limit == 10.0,
+        "DLY0 upper_disp_limit (%g) == 10", buf.upper_disp_limit);
+}
+
 /*
  * This test verifies the behavior of seq using Specified for SELM
  * The behavior should be the same for all the DOLx
@@ -34,7 +55,7 @@ void testSeqSpecified(void){
 
 
 MAIN(eventTest) {
-    testPlan(4*16);
+    testPlan(4*16 + 4);
 
     testdbPrepare();
 
@@ -47,6 +68,7 @@ MAIN(eventTest) {
     testIocInitOk();
     eltc(1);
 
+    testSeqDlyLimits();
     testSeqSpecified();
 
     testIocShutdownOk();