diff,difftool: Don't use the {0,2} notation in usage strings

This was the only occurence of that usage, and square brackets are
sufficient and already well-established for that purpose.

Signed-off-by: Štěpán Němec <stepnem@gmail.com>
Acked-by: Sverre Rabbelier <srabbelier@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff --git a/Documentation/git-diff.txt b/Documentation/git-diff.txt
index dd1fb32..61728f6 100644
--- a/Documentation/git-diff.txt
+++ b/Documentation/git-diff.txt
@@ -8,7 +8,7 @@
 
 SYNOPSIS
 --------
-'git diff' [<common diff options>] <commit>{0,2} [--] [<path>...]
+'git diff' [<common diff options>] [<commit> [<commit>]] [--] [<path>...]
 
 DESCRIPTION
 -----------
diff --git a/Documentation/git-difftool.txt b/Documentation/git-difftool.txt
index 8250bad..a02e3b5 100644
--- a/Documentation/git-difftool.txt
+++ b/Documentation/git-difftool.txt
@@ -7,7 +7,7 @@
 
 SYNOPSIS
 --------
-'git difftool' [<options>] <commit>{0,2} [--] [<path>...]
+'git difftool' [<options>] [<commit> [<commit>]] [--] [<path>...]
 
 DESCRIPTION
 -----------
diff --git a/builtin/diff.c b/builtin/diff.c
index a43d326..945e758 100644
--- a/builtin/diff.c
+++ b/builtin/diff.c
@@ -22,7 +22,7 @@
 };
 
 static const char builtin_diff_usage[] =
-"git diff <options> <rev>{0,2} -- <path>*";
+"git diff [<options>] [<commit> [<commit>]] [--] [<path>...]";
 
 static void stuff_change(struct diff_options *opt,
 			 unsigned old_mode, unsigned new_mode,