tests: add missing `head` for when things go wrong
See comment above the changed line, you can get a millions of line of output in
case of failure. When don't need to have them all.
Differential Revision: https://phab.mercurial-scm.org/D11780
--- a/tests/test-lfs-largefiles.t Tue Nov 23 16:32:56 2021 +0100
+++ b/tests/test-lfs-largefiles.t Mon Oct 25 15:11:53 2021 +0200
@@ -345,7 +345,7 @@
breaks you can get 1048576 lines of +y in the output, which takes a looooooong
time to print.
$ hg diff -r 2:3 | head -n 20
- $ hg diff -r 2:6
+ $ hg diff -r 2:6 | head -n 20
diff -r e989d0fa3764 -r 752e3a0d8488 large.bin
--- a/large.bin Thu Jan 01 00:00:00 1970 +0000
+++ b/large.bin Thu Jan 01 00:00:00 1970 +0000