The die() message that may occur in module_name() is not really relevant
to the user when called from module_clone(); the latter handles the
"failure" (no submodule mapping) anyway.
Analysis of other callsites is left to future work.
Acked-by: Jens Lehmann <Jens.Lehmann@web.de> Signed-off-by: Tay Ray Chuan <rctay89@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>