Fix comment

The last argument of smgrextend() was renamed from isTemp to skipFsync
in debcec7dc31a992703911a9953e299c8d730c778, but the comments at two
call sites were not updated.

src/backend/access/heap/rewriteheap.c

@@ -703,10 +703,9 @@ raw_heap_insert(RewriteState state, HeapTuple tup)
 							true);
 
 			/*
-			 * Now write the page. We say isTemp = true even if it's not a
+			 * Now write the page. We say skipFsync = true because there's no
-			 * temp table, because there's no need for smgr to schedule an
+			 * need for smgr to schedule an fsync for this write; we'll do it
-			 * fsync for this write; we'll do it ourselves in
+			 * ourselves in end_heap_rewrite.
-			 * end_heap_rewrite.
 			 */
 			RelationOpenSmgr(state->rs_new_rel);
 

src/backend/catalog/storage.c

@@ -390,9 +390,9 @@ RelationCopyStorage(SMgrRelation src, SMgrRelation dst,
 		PageSetChecksumInplace(page, blkno);
 
 		/*
-		 * Now write the page.  We say isTemp = true even if it's not a temp
+		 * Now write the page.  We say skipFsync = true because there's no
-		 * rel, because there's no need for smgr to schedule an fsync for this
+		 * need for smgr to schedule an fsync for this write; we'll do it
-		 * write; we'll do it ourselves below.
+		 * ourselves below.
 		 */
 		smgrextend(dst, forkNum, blkno, buf.data, true);
 	}