[XFS] kill di_mode checks after xfs_iget

Unless XFS_IGET_CREATE is passed xfs_iget will return ENOENT if it
encounters an inode with di_mode == 0. Remove the duplicated checks in the
callers.

(the log recovery case is not touched for now)

SGI-PV: 976035
SGI-Modid: xfs-linux-melb:xfs-kern:30898a

Signed-off-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>

fs/xfs/quota/xfs_qm.c

@@ -1737,12 +1737,6 @@ xfs_qm_dqusage_adjust(
 		return error;
 	}
 
-	if (ip->i_d.di_mode == 0) {
-		xfs_iput_new(ip, XFS_ILOCK_EXCL);
-		*res = BULKSTAT_RV_NOTHING;
-		return XFS_ERROR(ENOENT);
-	}
-
 	/*
 	 * Obtain the locked dquots. In case of an error (eg. allocation
 	 * fails for ENOSPC), we return the negative of the error number