Commentary: Fix spelling in C++ comments (#3797) (#3798)

src/V3DfgPasses.cpp

@@ -226,7 +226,7 @@ void V3DfgPasses::removeUnused(DfgGraph& dfg) {
 
     // Head of work list. Note that we want all next pointers in the list to be non-zero (including
     // that of the last element). This allows as to do two important things: detect if an element
-    // is in the list by checking for a non-zero next poitner, and easy prefetching without
+    // is in the list by checking for a non-zero next pointer, and easy prefetching without
     // conditionals. The address of the graph is a good sentinel as it is a valid memory address,
     // and we can easily check for the end of the list.
     DfgVertex* const sentinelp = reinterpret_cast<DfgVertex*>(&dfg);