* lib/utils.exp (grep): Remove reference to "NULL" in comment.

* testsuite/lib/util-defs.exp (util_start): Likewise.

ChangeLog

@@ -1,3 +1,8 @@
+2018-11-30  Ben Elliston  <bje@gnu.org>
+
+	* lib/utils.exp (grep): Remove reference to "NULL" in comment.
+	* testsuite/lib/util-defs.exp (util_start): Likewise.
+
 2018-11-30  Ben Elliston  <bje@gnu.org>
 
 	* doc/dejagnu.texi: (verbose procedure): Improve documentation.

lib/utils.exp

@@ -162,7 +162,7 @@ proc which { file } {
 }
 
 # Looks for occurrences of a string in a file.
-#     return:list of lines that matched or NULL if none match.
+#     return:list of lines that matched or empty string if none match.
 #     args:  first arg is the filename,
 #            second is the pattern,
 #            third are any options.

testsuite/lib/util-defs.exp

@@ -73,7 +73,7 @@ proc util_test { args } {
 #
 # Run the utility
 #
-# Return NULL or the output.
+# Return the output or an empty string.
 #
 
 proc util_start { args } {