ext4: Convert bg_inode_bitmap and bg_inode_table

Convert bg_inode_bitmap and bg_inode_table to bg_inode_bitmap_lo
and bg_inode_table_lo.  This helps in finding BUGs due to
direct partial access of these split 64 bit values

Also fix one direct partial access

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
diff --git a/fs/ext4/balloc.c b/fs/ext4/balloc.c
index 5927687..e906b65 100644
--- a/fs/ext4/balloc.c
+++ b/fs/ext4/balloc.c
@@ -115,7 +115,7 @@
 		/* Set bits for block and inode bitmaps, and inode table */
 		ext4_set_bit(ext4_block_bitmap(sb, gdp) - start, bh->b_data);
 		ext4_set_bit(ext4_inode_bitmap(sb, gdp) - start, bh->b_data);
-		for (bit = le32_to_cpu(gdp->bg_inode_table) - start,
+		for (bit = (ext4_inode_table(sb, gdp) - start),
 		     bit_max = bit + sbi->s_itb_per_group; bit < bit_max; bit++)
 			ext4_set_bit(bit, bh->b_data);