t7800: remove whitespace before redirect

Signed-off-by: David Aguilar <davvid@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

t/t7800-difftool.sh

@@ -428,7 +428,7 @@ run_dir_diff_test 'difftool --dir-diff branch from subdirectory' '
 		git difftool --dir-diff $symlinks --extcmd ls branch >output &&
 		# "sub" must only exist in "right"
 		# "file" and "file2" must be listed in both "left" and "right"
-		grep sub output > sub-output &&
+		grep sub output >sub-output &&
 		test_line_count = 1 sub-output &&
 		grep file"$" output >file-output &&
 		test_line_count = 2 file-output &&