ext4: rename ext4_claim_free_blocks() to ext4_claim_free_clusters()

This function really claims a number of free clusters, not blocks, so
rename it so it's clearer what's going on.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index 1473c06..f976386 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -1773,8 +1773,8 @@
 					 unsigned int flags,
 					 unsigned long *count,
 					 int *errp);
-extern int ext4_claim_free_blocks(struct ext4_sb_info *sbi,
-				  s64 nblocks, unsigned int flags);
+extern int ext4_claim_free_clusters(struct ext4_sb_info *sbi,
+				    s64 nclusters, unsigned int flags);
 extern ext4_fsblk_t ext4_count_free_clusters(struct super_block *);
 extern void ext4_check_blocks_bitmap(struct super_block *);
 extern struct ext4_group_desc * ext4_get_group_desc(struct super_block * sb,