Replace DCHECK_NOTNULL in void context in dsi/logger/cpp/LoggerBase.c…

…pp +3

Summary:
`DCHECK_NOTNULL` returns its argument, which triggers `-Wunused-value` warnings in void context.
Replace it with `DCHECK_NE($$, nullptr)` which conveys the same intent without the warning.

(3 files modified.)

Reviewed By: Orvid

Differential Revision: D69618772

fbshipit-source-id: 14cecb6ef664db490e67a18d20080b7160d61da1

folly/io/IOBuf.cpp

@@ -799,7 +799,7 @@ IOBuf IOBuf::cloneCoalescedAsValueWithHeadroomTailroom(
   auto current = this;
   do {
     if (current->length() > 0) {
-      DCHECK_NOTNULL(current->data());
+      DCHECK_NE(current->data(), nullptr);
       DCHECK_LE(current->length(), newBuf.tailroom());
       memcpy(newBuf.writableTail(), current->data(), current->length());
       newBuf.append(current->length());