performtest: use -u with diff

Unified diffs are the only sane option.  When calling diff, pass the
-u option.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>

1 files changed, 1 insertions, 1 deletions

diff --git a/test/performtest.pl b/test/performtest.pl
index 5574fc6c..78e22f6e 100755
--- a/test/performtest.pl
+++ b/test/performtest.pl
@@ -100,7 +100,7 @@ sub perform {
                 if($diff) {
                     for(@failedfiles) {
                         if($_ eq $stdoutfile or $_ eq $stderrfile) {
-                            system "diff golden/$testname/$subname/$_ $outputdir/$testname/$subname/$_";
+                            system "diff -u golden/$testname/$subname/$_ $outputdir/$testname/$subname/$_";
                             print "\n";
                         }
                     }