ext4: Clean up calls to ext4_get_group_desc()

If the caller isn't planning on modifying the block group descriptors,
there's no need to pass in a pointer to a struct buffer_head.  Nuking
this saves a tiny amount of CPU time and stack space usage.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

fs/ext4/ialloc.c

@@ -347,7 +347,6 @@ static int find_group_flex(struct super_block *sb, struct inode *parent,
 {
 	struct ext4_sb_info *sbi = EXT4_SB(sb);
 	struct ext4_group_desc *desc;
-	struct buffer_head *bh;
 	struct flex_groups *flex_group = sbi->s_flex_groups;
 	ext4_group_t parent_group = EXT4_I(parent)->i_block_group;
 	ext4_group_t parent_fbg_group = ext4_flex_group(sbi, parent_group);
@@ -402,7 +401,7 @@ static int find_group_flex(struct super_block *sb, struct inode *parent,
 found_flexbg:
 	for (i = best_flex * flex_size; i < ngroups &&
 		     i < (best_flex + 1) * flex_size; i++) {
-		desc = ext4_get_group_desc(sb, i, &bh);
+		desc = ext4_get_group_desc(sb, i, NULL);
 		if (ext4_free_inodes_count(sb, desc)) {
 			*best_group = i;
 			goto out;

fs/ext4/super.c

@@ -1660,7 +1660,6 @@ static int ext4_fill_flex_info(struct super_block *sb)
 {
 	struct ext4_sb_info *sbi = EXT4_SB(sb);
 	struct ext4_group_desc *gdp = NULL;
-	struct buffer_head *bh;
 	ext4_group_t flex_group_count;
 	ext4_group_t flex_group;
 	int groups_per_flex = 0;
@@ -1693,7 +1692,7 @@ static int ext4_fill_flex_info(struct super_block *sb)
 	}
 
 	for (i = 0; i < sbi->s_groups_count; i++) {
-		gdp = ext4_get_group_desc(sb, i, &bh);
+		gdp = ext4_get_group_desc(sb, i, NULL);
 
 		flex_group = ext4_flex_group(sbi, i);
 		atomic_set(&sbi->s_flex_groups[flex_group].free_inodes,