[PATCH] Remove --no-gui option from difftool usage string

[Denton Liu <liu.denton@xxxxxxxxx>]

The --no-gui option not documented in the manpage, nor is it actually
used in the source code. This change removes it from the usage help
that's printed.

Signed-off-by: Denton Liu <liu.denton@xxxxxxxxx>
---
 git-difftool.perl | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/git-difftool.perl b/git-difftool.perl
index a5790d03a..657d5622d 100755
--- a/git-difftool.perl
+++ b/git-difftool.perl
@@ -29,8 +29,8 @@ sub usage
 	print << 'USAGE';
 usage: git difftool [-t|--tool=<tool>] [--tool-help]
                     [-x|--extcmd=<cmd>]
-                    [-g|--gui] [--no-gui]
-                    [--prompt] [-y|--no-prompt]
+                    [-g|--gui] [--prompt]
+                    [-y|--no-prompt]
                     [-d|--dir-diff]
                     ['git diff' options]
 USAGE
-- 
2.11.0