ext4: fix up rb_root initializations to use RB_ROOT

ext4 uses rb_node = NULL; to zero rb_root at few places.  Using
RB_ROOT as the initializer is more portable in case the underlying
implementation of rbtrees changes in the future.

Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: Eric Paris <eparis@redhat.com>

1 files changed, 2 insertions, 2 deletions

diff --git a/fs/ext4/block_validity.c b/fs/ext4/block_validity.c
index a60ab9aad57d..983f0e127493 100644
--- a/fs/ext4/block_validity.c
+++ b/fs/ext4/block_validity.c
@@ -205,14 +205,14 @@ void ext4_release_system_zone(struct super_block *sb)
                 entry = rb_entry(n, struct ext4_system_zone, node);
                 kmem_cache_free(ext4_system_zone_cachep, entry);
                 if (!parent)
-                        EXT4_SB(sb)->system_blks.rb_node = NULL;
+                        EXT4_SB(sb)->system_blks = RB_ROOT;
                 else if (parent->rb_left == n)
                         parent->rb_left = NULL;
                 else if (parent->rb_right == n)
                         parent->rb_right = NULL;
                 n = parent;
         }
-        EXT4_SB(sb)->system_blks.rb_node = NULL;
+        EXT4_SB(sb)->system_blks = RB_ROOT;
 }
 
 /*