test: add regex check in test-buffer-bad-overload

Creating a buffer from a number should throw an error with a message
that describes the issue.

PR-URL: https://github.com/nodejs/node/pull/10038
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>

test/parallel/test-buffer-bad-overload.js

@@ -8,7 +8,7 @@ assert.doesNotThrow(function() {
 
 assert.throws(function() {
   Buffer.from(10, 'hex');
-});
+}, /^TypeError: "value" argument must not be a number$/);
 
 assert.doesNotThrow(function() {
   Buffer.from('deadbeaf', 'hex');