Fuzzer for libdm's dm-linear devices creation

Create a fuzzer that fuzzes the parameters used for the creation
of dm-linear tables through libdm.
This fuzzer is based on libdm::DmLinear.

Bug: none
Test: dm_linear_fuzzer
Change-Id: I052144c6eb0db4fa6a37b5e54fbcb8193e5dc88f
Signed-off-by: Alessio Balsini <balsini@google.com>