ext4: remove unnecessary ext4_get_group_info in ext4_mb_load_buddy

ext4_mb_load_buddy() calls ext4_get_group_info() for setting both
"grp" and "e4b->bd_info", but it could do "e4b->bd_info = grp".

Reported-by:  Andreas Dilger <adilger@whamcloud.com>
Signed-off-by: Tao Ma <boyu.mt@taobao.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
index 037f680..447c0f3 100644
--- a/fs/ext4/mballoc.c
+++ b/fs/ext4/mballoc.c
@@ -1126,7 +1126,7 @@
 	grp = ext4_get_group_info(sb, group);
 
 	e4b->bd_blkbits = sb->s_blocksize_bits;
-	e4b->bd_info = ext4_get_group_info(sb, group);
+	e4b->bd_info = grp;
 	e4b->bd_sb = sb;
 	e4b->bd_group = group;
 	e4b->bd_buddy_page = NULL;