Comment extending and cleanup

contrib/pg_upgrade/info.c

@@ -607,15 +607,16 @@ get_rel_infos(migratorContext *ctx, const DbInfo *dbinfo,
 			}
 
 			/*
-			 * Get contents of pg_aovisimap_<oid>
+			 * Get contents of the auxiliary pg_aovisimap_<oid> relation.  In
+			 * GPDB 4.3, the pg_aovisimap_<oid>.visimap field was of type "bit
+			 * varying", but we didn't actually store a valid "varbit" datum in
+			 * it. Because of that, we won't get the valid data out by calling
+			 * the varbit output function on it.  Create a little function to
+			 * blurp out its content as a bytea instead. in 5.0 and above, the
+			 * datatype is also nominally a bytea.
 			 *
-			 * In GPDB 4.3, the pg_aovisimap_<oid>.visimap field was of type "bit varying",
-			 * but we didn't actually store a valid "varbit" datum in it. Because of that,
-			 * we won't get the valid data out by calling the varbit output function on it.
-			 * Create a little function to blurp out its content as a bytea instead. in
-			 * 5.0 and above, the datatype is also nominally a bytea.
-			 *
-			 * pg_aovisimap_<oid> is identical for row and column oriented tables.
+			 * pg_aovisimap_<oid> is identical for row and column oriented
+			 * tables.
 			 */
 			if (GET_MAJOR_VERSION(ctx->old.major_version) <= 802 && whichCluster == CLUSTER_OLD)
 			{