GFS2: The war on bloat

The following patch shrinks the gfs2_args structure which is embedded in
every GFS2 superblock. It cuts down the size of the options to a single
unsigned int (the 13 bits of bitfields will be rounded up to that size
by the compiler) from the current 11 unsigned ints. So on x86 thats 44
bytes shrinking to 4 bytes, in each and every GFS2 superblock.

Signed-off-by: Steven Whitehouse <swhitho@redhat.com>