[LTP] [PATCH 1/1] prepare_lvm.sh: Use $TMPDIR instead of custom $LVM_DIR

[Petr Vorel]

> Hi,
> I still think there's a valid use case for creating the LVM backing files on
> a different path than TMPDIR because they can be huge. But LVM_DIR should
> default to TMPDIR if not explicitly set. So how about this?

> TMPDIR="${TMPDIR:-/tmp}"
> LVM_DIR="${LVM_DIR:-$TMPDIR}"

Thanks for your review, Martin.
Make sense. And it will be backward compatible.
I'll send v2.

Kind regards,
Petr