[XFS] Ensure errors from xfs_bdstrat() are correctly checked.

xfsbdstrat() is declared to return an error. That is never checked because
the error is propagated by the xfs_buf_t that is passed through the
function.

Mark xfsbdstrat() as returning void and comment the prototype on the
methods needed for error checking.

SGI-PV: 980084
SGI-Modid: xfs-linux-melb:xfs-kern:30823a

Signed-off-by: David Chinner <dgc@sgi.com>
Signed-off-by: Niv Sardi <xaiki@sgi.com>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
diff --git a/fs/xfs/xfs_vnodeops.c b/fs/xfs/xfs_vnodeops.c
index ca38fb9..dd4621e 100644
--- a/fs/xfs/xfs_vnodeops.c
+++ b/fs/xfs/xfs_vnodeops.c
@@ -3825,7 +3825,8 @@
 		XFS_BUF_READ(bp);
 		XFS_BUF_SET_ADDR(bp, XFS_FSB_TO_DB(ip, imap.br_startblock));
 		xfsbdstrat(mp, bp);
-		if ((error = xfs_iowait(bp))) {
+		error = xfs_iowait(bp);
+		if (error) {
 			xfs_ioerror_alert("xfs_zero_remaining_bytes(read)",
 					  mp, bp, XFS_BUF_ADDR(bp));
 			break;
@@ -3837,7 +3838,8 @@
 		XFS_BUF_UNREAD(bp);
 		XFS_BUF_WRITE(bp);
 		xfsbdstrat(mp, bp);
-		if ((error = xfs_iowait(bp))) {
+		error = xfs_iowait(bp);
+		if (error) {
 			xfs_ioerror_alert("xfs_zero_remaining_bytes(write)",
 					  mp, bp, XFS_BUF_ADDR(bp));
 			break;