doc txt & -h consistency: use "[<label>...]" for "zero or more"

Correct uses of "<label>..." where we really meant to say
"[<label>...]", i.e. the command in question taken an optional set of
"<label>". As the CodingGuidelines notes "[o]ptional parts [should be]
enclosed in square brackets".

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Documentation/git-clean.txt

@@ -8,7 +8,7 @@ git-clean - Remove untracked files from the working tree
 SYNOPSIS
 --------
 [verse]
-'git clean' [-d] [-f] [-i] [-n] [-q] [-e <pattern>] [-x | -X] [--] <pathspec>...
+'git clean' [-d] [-f] [-i] [-n] [-q] [-e <pattern>] [-x | -X] [--] [<pathspec>...]
 
 DESCRIPTION
 -----------

builtin/clean.c

@@ -26,7 +26,7 @@ static struct string_list del_list = STRING_LIST_INIT_DUP;
 static unsigned int colopts;
 
 static const char *const builtin_clean_usage[] = {
-	N_("git clean [-d] [-f] [-i] [-n] [-q] [-e <pattern>] [-x | -X] [--] <pathspec>..."),
+	N_("git clean [-d] [-f] [-i] [-n] [-q] [-e <pattern>] [-x | -X] [--] [<pathspec>...]"),
 	NULL
 };
 

builtin/commit.c

@@ -45,7 +45,7 @@ static const char * const builtin_commit_usage[] = {
 };
 
 static const char * const builtin_status_usage[] = {
-	N_("git status [<options>] [--] <pathspec>..."),
+	N_("git status [<options>] [--] [<pathspec>...]"),
 	NULL
 };