diff: --pickaxe-all typofix

When I was fixing fuzzies as I updating po/id.po for 2.33.0 l10n round,
I noticed a triple-dash typo (--pickaxe-all) at diff.c, which according
to git-diff(1) manpage, the correct option name should be --pickaxe-all.

Fix the typo.

Signed-off-by: Bagas Sanjaya <bagasdotme@gmail.com>
Acked-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff --git a/diff.c b/diff.c
index fe3abac..084f7b1 100644
--- a/diff.c
+++ b/diff.c
@@ -4636,7 +4636,7 @@ void diff_setup_done(struct diff_options *options)
 		die(_("-G and --pickaxe-regex are mutually exclusive, use --pickaxe-regex with -S"));
 
 	if (HAS_MULTI_BITS(options->pickaxe_opts & DIFF_PICKAXE_KINDS_ALL_OBJFIND_MASK))
-		die(_("---pickaxe-all and --find-object are mutually exclusive, use --pickaxe-all with -G and -S"));
+		die(_("--pickaxe-all and --find-object are mutually exclusive, use --pickaxe-all with -G and -S"));
 
 	/*
 	 * Most of the time we can say "there are changes"