Changes

filesystem: do not decode short TransRecEF records

A TransRecEF is based on a TransparentEF. This means that a TransRecEF
is basically normal TransparentEF that holds a record oriented data
structure. This also requires that the total length of the TransRecEF
is a multiple of the record length of the data structure that is stored
in it. When this is not the case, the last record will be cut short and
the decoding will fail. We should guard against this case.

Related: OS#6598
Change-Id: Ib1dc4d7ce306f1f0b080bb4b6abc36e72431d3fa