Fix an apparent copy-paste error: A few lines earlier, a tag
"refs/tags/sometag" is created. Check for the (non-)existence of that
tag, not "somebranch", which is otherwise never mentioned in the
script.
Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu> Signed-off-by: Junio C Hamano <gitster@pobox.com>