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/balloc.c b/fs/ext4/balloc.c
index 3d07c35..af0c535 100644
--- a/fs/ext4/balloc.c
+++ b/fs/ext4/balloc.c
@@ -445,11 +445,11 @@
 	return 0;
 }
 
-int ext4_claim_free_blocks(struct ext4_sb_info *sbi,
-			   s64 nblocks, unsigned int flags)
+int ext4_claim_free_clusters(struct ext4_sb_info *sbi,
+			     s64 nclusters, unsigned int flags)
 {
-	if (ext4_has_free_blocks(sbi, nblocks, flags)) {
-		percpu_counter_add(&sbi->s_dirtyclusters_counter, nblocks);
+	if (ext4_has_free_blocks(sbi, nclusters, flags)) {
+		percpu_counter_add(&sbi->s_dirtyclusters_counter, nclusters);
 		return 0;
 	} else
 		return -ENOSPC;