fstests: add missing remove of the $seqres.full file for some tests

fstests: add missing remove of the $seqres.full file for some tests

Some test cases are missing the 'rm -f $seqres.full' line but are appending
to that file, so everytime they run that file gets bigger and bigger (some
of them are using about a dozen megabytes on one of my test boxes).

So just add the 'rm -f $seqres.full' line to them, together with the comment
that the 'new' script generates for new test cases.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Eryu Guan <guaneryu@gmail.com>