p0004: simplify calls of test-lazy-init-name-hash

p0004: simplify calls of test-lazy-init-name-hash

The test library puts helpers into $PATH, so we can simply call them
without specifying their location.

The suffix $X is also not necessary because .exe files on Windows can be
started without specifying their extension, and on other platforms it's
empty anyway.

Signed-off-by: Rene Scharfe <l.s.r@web.de>
Acked-by: Jeff Hostetler <git@jeffhostetler.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>