ext4: Make ext4_group_t be an unsigned int

Nearly all places in the ext3/4 code which uses "unsigned long" is
probably a bug, since on 32-bit systems a ulong a 32-bits, which means
we are wasting stack space on 64-bit systems.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index 9ba9fd6..e9aacec 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -965,7 +965,7 @@
 #define ERR_BAD_DX_DIR	-75000
 
 void ext4_get_group_no_and_offset(struct super_block *sb, ext4_fsblk_t blocknr,
-			unsigned long *blockgrpp, ext4_grpblk_t *offsetp);
+			ext4_group_t *blockgrpp, ext4_grpblk_t *offsetp);
 
 extern struct proc_dir_entry *ext4_proc_root;