pull: use $curr_branch_short more

One of the first things git-pull.sh does is setting $curr_branch to the target of HEAD and $curr_branch_short to the same but with the leading "refs/heads/" removed. Simplify the code by using $curr_branch_short instead of setting $curr_branch to the same shortened value. The only other use of $curr_branch in that function doesn't have to be replaced with $curr_branch_short because it just checks if the string is empty. That property is the same with or without the prefix unless HEAD points to "refs/heads/" alone, which is invalid. Noticed-by: Felipe Contreras <felipe.contreras@gmail.com> Signed-off-by: Rene Scharfe <l.s.r@web.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>