Add block device option in runltplite.sh

Hi,

as previously reported on the mailing list at least one test (access06) included in runltplite.sh requires a block device to be defined and reports a test failure if not present. However, runltplite.sh provided no command line option to define a block device or block device file system type.

With this change runltplite.sh sources the functions in runltp and provides an option to specify the block device (-b) and block device filesystem type (-B) just like runltp.

NOTE: the underlying assumption is that both runltp and runltplite.sh are located in the same directory.

Thanks & cheerio, Harry.