nilfs2: use i_blocksize()

Since i_blocksize() helper has been defined in fs.h, use it instead of
open-coding.

Link: http://lkml.kernel.org/r/[e-mail]
Signed-off-by: Geliang Tang <[e-mail]>
Signed-off-by: Ryusuke Konishi <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>
Signed-off-by: Linus Torvalds <[e-mail]>

fs/nilfs2/alloc.c

···
 static inline unsigned long
 nilfs_palloc_groups_per_desc_block(const struct inode *inode)
 {
-	return (1UL << inode->i_blkbits) /
+	return i_blocksize(inode) /
 		sizeof(struct nilfs_palloc_group_desc);
 }
 

fs/nilfs2/btree.c

···
 
 static int nilfs_btree_node_size(const struct nilfs_bmap *btree)
 {
-	return 1 << btree->b_inode->i_blkbits;
+	return i_blocksize(btree->b_inode);
 }
 
 static int nilfs_btree_nchildren_per_block(const struct nilfs_bmap *btree)