QA test updates - fixes for pquota, extsize, fsstress, and ensure mount options passed through to test_dev.

Merge of master-melb:xfs-cmds:24763a by kenmcd.

tools/srcdiff

@@ -80,6 +80,9 @@ sub straightdiff {
 	} elsif ($? != 0) {
 	        printf("\t%-35s ... FAILED\n(%s/%s differs to %s/%s)\n",
 			$file, $prefix1, $file, $prefix2, $file);
+		if (defined($xdiff)) {
+			`$xdiff $prefix1/$file $prefix2/$file`;
+		}
 	}
 }