dm-latency: fix a typo in dm.c

Last time when I merge a patch, a typo (an extra 's') was introduced into
0002-dm-latency-move-mapped_device-struct-into-dm_h.patch.

This patch removes the singole extra 's' in dm.c
dm-latency: update pre-compiled dm-mod.ko

rebuild dm-mod.ko on a rhel5 server.
dm-latency: fix initrd name in modules-setup.sh

initrd name has an ".img" postfix, this commit fixes initrd name in
modules-setup.sh