xfs: fix the xfs_log_iovec i_addr type

By making this member a void pointer we can get rid of a lot of pointless
casts.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>

diff --git a/fs/xfs/xfs_log_cil.c b/fs/xfs/xfs_log_cil.c
index 5eaeede..31e4ea2 100644
--- a/fs/xfs/xfs_log_cil.c
+++ b/fs/xfs/xfs_log_cil.c
@@ -552,7 +552,7 @@
 	thdr.th_type = XFS_TRANS_CHECKPOINT;
 	thdr.th_tid = tic->t_tid;
 	thdr.th_num_items = num_iovecs;
-	lhdr.i_addr = (xfs_caddr_t)&thdr;
+	lhdr.i_addr = &thdr;
 	lhdr.i_len = sizeof(xfs_trans_header_t);
 	lhdr.i_type = XLOG_REG_TYPE_TRANSHDR;
 	tic->t_curr_res -= lhdr.i_len + sizeof(xlog_op_header_t);