ext4: Use high 16 bits of the block group descriptor's free counts fields

Rename the lower bits with suffix _lo and add helper
to access the values. Also rename bg_itable_unused_hi
to bg_pad as in e2fsprogs.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
diff --git a/fs/ext4/resize.c b/fs/ext4/resize.c
index 92034d2..2d24f42 100644
--- a/fs/ext4/resize.c
+++ b/fs/ext4/resize.c
@@ -866,8 +866,8 @@
 	ext4_block_bitmap_set(sb, gdp, input->block_bitmap); /* LV FIXME */
 	ext4_inode_bitmap_set(sb, gdp, input->inode_bitmap); /* LV FIXME */
 	ext4_inode_table_set(sb, gdp, input->inode_table); /* LV FIXME */
-	gdp->bg_free_blocks_count = cpu_to_le16(input->free_blocks_count);
-	gdp->bg_free_inodes_count = cpu_to_le16(EXT4_INODES_PER_GROUP(sb));
+	ext4_free_blks_set(sb, gdp, input->free_blocks_count);
+	ext4_free_inodes_set(sb, gdp, EXT4_INODES_PER_GROUP(sb));
 	gdp->bg_flags |= cpu_to_le16(EXT4_BG_INODE_ZEROED);
 	gdp->bg_checksum = ext4_group_desc_csum(sbi, input->group, gdp);