xfs: fix boolreturn.cocci warnings

fs/xfs/xfs_log.c:1062:9-10: WARNING: return of 0/1 in function 'xfs_log_need_covered' with return type bool

 Return statements in functions returning bool should use
 true/false instead of 1/0.
Generated by: scripts/coccinelle/misc/boolreturn.cocci

Fixes: 37444fc4 ("xfs: lift writable fs check up into log worker task")
CC: Brian Foster <bfoster@redhat.com>
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: kernel test robot <lkp@intel.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>