xfs: don't clear the "dinode core" in xfs_inode_alloc

The xfs_icdinode structure just contains a random mix of inode field,
which are all read from the on-disk inode and mostly not looked at
before reading the inode or initializing a new inode cluster.  The
only exceptions are the forkoff and blocks field, which are used
in sanity checks for freshly allocated inodes.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>

fs/xfs/xfs_icache.c

@@ -63,8 +63,9 @@ xfs_inode_alloc(
 	memset(&ip->i_df, 0, sizeof(ip->i_df));
 	ip->i_flags = 0;
 	ip->i_delayed_blks = 0;
-	memset(&ip->i_d, 0, sizeof(ip->i_d));
 	ip->i_d.di_flags2 = mp->m_ino_geo.new_diflags2;
+	ip->i_d.di_nblocks = 0;
+	ip->i_d.di_forkoff = 0;
 	ip->i_sick = 0;
 	ip->i_checked = 0;
 	INIT_WORK(&ip->i_ioend_work, xfs_end_io);