Do not check if getcwd() result begins with a slash.

Do not check if getcwd() result begins with a slash.

In user space, and for getcwd(), the check to see if the
resulting path begins with a '/' does not make sense.  This is
merely a mistake by Linus who is so used to code for the kernel,
where a d_path() return value pathname can be either a real
path, or something like "pipe:[8003]", and the difference is the
'/' at the beginning.

Pointed out by Dscho, Matthias Lederhofer and clarified by Linus.

Signed-off-by: Junio C Hamano <gitster@pobox.com>