[XFS] Fix mknod regression

This was broken by my '[XFS] simplify xfs_create/mknod/symlink prototype',
which assigned the re-shuffled ondisk dev_t back to the rdev variable in
xfs_vn_mknod. Because of that i_rdev is set to the ondisk dev_t instead of
the linux dev_t later down the function.

Fortunately the fix for it is trivial: we can just remove the assignment
because xfs_revalidate_inode has done the proper job before unlocking the
inode.

SGI-PV: 974873
SGI-Modid: xfs-linux-melb:xfs-kern:30273a
Signed-off-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: David Chinner <dgc@sgi.com>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>

fs/xfs/linux-2.6/xfs_iops.c

@@ -332,9 +332,7 @@ xfs_vn_mknod(
 		ASSERT(vp);
 		ip = vn_to_inode(vp);
 
-		if (S_ISCHR(mode) || S_ISBLK(mode))
-			ip->i_rdev = rdev;
-		else if (S_ISDIR(mode))
+		if (S_ISDIR(mode))
 			xfs_validate_fields(ip);
 		d_instantiate(dentry, ip);
 		xfs_validate_fields(dir);