[GFS2] Drop log lock on I/O error & tidy up

This patch drops the log spinlock when an I/O error occurs
to avoid any possible problems in case of blocking or
recursion in the I/O error routine. It also has a few
cosmetic changes to tidy up various other files.

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

diff --cc fs/gfs2/meta_io.c
Simple merge

diff --cc fs/gfs2/ops_inode.c
Simple merge

diff --cc fs/gfs2/page.c
Simple merge

diff --cc fs/gfs2/unlinked.c
Simple merge