At the moment modules in modules.dep are matched even on a submatch
e.g. looking up "msm" ends up matching "snd-soc-msm8916-digital.ko"
instead of "msm.ko". To fix this, disallow submatches using ^ and $.
I misread what strings.Trim does, the 2nd param is a _cut set_, so this
was removing any occurance any characters in the 2nd param. Since the
file extension is always a suffix, this uses TrimSuffix.
Fixes a bug where 'virtio_blk.ko' was being trimmed to 'virtio_bl'
