ext4: remove unused metadata accounting variables

Two variables in ext4_inode_info, i_reserved_meta_blocks and
i_allocated_meta_blocks, are unused.  Removing them saves a little
memory per in-memory inode and cleans up clutter in several tracepoints.
Adjust tracepoint output from ext4_alloc_da_blocks() for consistency
and fix a typo and whitespace near these changes.

Signed-off-by: Eric Whitney <enwlinux@gmail.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Jan Kara <jack@suse.cz>
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index 9ebde0c..dcbcd9d 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -961,7 +961,7 @@ struct ext4_inode_info {
 	/*
 	 * i_block_group is the number of the block group which contains
 	 * this file's inode.  Constant across the lifetime of the inode,
-	 * it is ued for making block allocation decisions - we try to
+	 * it is used for making block allocation decisions - we try to
 	 * place a file's data blocks near its inode block, and new inodes
 	 * near to their parent directory's inode.
 	 */
@@ -1049,10 +1049,8 @@ struct ext4_inode_info {
 	ext4_group_t	i_last_alloc_group;
 
 	/* allocation reservation info for delalloc */
-	/* In case of bigalloc, these refer to clusters rather than blocks */
+	/* In case of bigalloc, this refer to clusters rather than blocks */
 	unsigned int i_reserved_data_blocks;
-	unsigned int i_reserved_meta_blocks;
-	unsigned int i_allocated_meta_blocks;
 	ext4_lblk_t i_da_metadata_calc_last_lblock;
 	int i_da_metadata_calc_len;