Documentation/git-bundle.txt: fix synopsis

The <git-rev-list args> are mandatory to git bundle create, not
optional.  The usage output of git bundle is already right on this.

Signed-off-by: Gerrit Pape <pape@smarden.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Documentation/git-bundle.txt

@@ -9,7 +9,7 @@ git-bundle - Move objects and refs by archive
 SYNOPSIS
 --------
 [verse]
-'git-bundle' create <file> [git-rev-list args]
+'git-bundle' create <file> <git-rev-list args>
 'git-bundle' verify <file>
 'git-bundle' list-heads <file> [refname...]
 'git-bundle' unbundle <file> [refname...]