[PATCH] kbuild: obey HOSTLOADLIBES_programname for single-file compilation

Single-file HOSTCC calls added the libraries from $(HOSTLOADLIBES),
but not from $(HOSTLOADLIBES_programname). Multi-file HOSTCC calls do
both.

This patch fixes that inconsistency.

Signed-Off-By: Matthias Urlichs <smurf@debian.org>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>