n future (i.e.
the locks will be sized proportionally with the max number of CPUs
and the hash chains sized proportinally with the size of physical memory)

In order to allow this, the gl_bucket member of struct gfs2_glock has
now become gl_hash, so we record the hash rather than a pointer to the
bucket itself.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
³