Updated dosfstools packages fix security vulnerabilities

Updated dosfstools package fixes security vulnerabilities: In dosfstools before 4.0, if the third to last entry was written on a FAT12 filesystem with an odd number of clusters, the second to last entry would be corrupted. This corruption may also lead to invalid memory accesses when the corrupted entry becomes out of bounds and is used later (CVE-2015-8872). In dosfstools before 4.0, the variable used for storing the FAT size (in bytes) was an unsigned int. Since the size in sectors read from the BPB was not sufficiently checked, this could end up being zero after multiplying it with the sector size while some offsets still stayed excessive. Ultimately it would cause segfaults when accessing FAT entries for which no memory was allocated (CVE-2016-4804).