Revert "Add more temporary debug logging, in 9.4 branch only."

This reverts commit eef1a609.
It's served its purpose.

src/backend/commands/indexcmds.c

@@ -773,8 +773,6 @@ DefineIndex(Oid relationId,
 
 	PopActiveSnapshot();
 	PrintSnapMgrStatus("concurrent index build, after PopActiveSnapshot");
-	elog(LOG, "concurrent index build: releasing snap %p with regd_count %d, active_count %d",
-		 snapshot, snapshot->regd_count, snapshot->active_count);
 	UnregisterSnapshot(snapshot);
 	PrintSnapMgrStatus("concurrent index build, after UnregisterSnapshot");
 	InvalidateCatalogSnapshot();

src/backend/utils/time/snapmgr.c

@@ -1411,7 +1411,7 @@ PrintSnapMgrStatus(const char *context)
 	for (active = ActiveSnapshot; active != NULL; active = active->as_next)
 		asdepth++;
 
-	elog(LOG, "%s: %d reg snaps, %d active snaps, first snap %p, cat snap %p, xmin %u",
+	elog(LOG, "%s: %d reg snaps, %d active snaps, cat snap %p, xmin %u",
 		 context, RegisteredSnapshots, asdepth,
-		 FirstXactSnapshot, CatalogSnapshot, MyPgXact->xmin);
+		 CatalogSnapshot, MyPgXact->xmin);
 }