ext4: block_validity: Remove unnecessary ‘NULL’ values from new_node

new_node is assigned first, so it does not need to initialize the
assignment.
Signed-off-by: Li zeming <zeming@nfschina.com>
Reviewed-by: Andreas Dilger <adilger@dilger.ca>
Link: https://patch.msgid.link/20240402022300.25858-1-zeming@nfschina.comSigned-off-by: Theodore Ts'o <tytso@mit.edu>

fs/ext4/block_validity.c

@@ -72,7 +72,7 @@ static int add_system_zone(struct ext4_system_blocks *system_blks,
 {
 	struct ext4_system_zone *new_entry, *entry;
 	struct rb_node **n = &system_blks->root.rb_node, *node;
-	struct rb_node *parent = NULL, *new_node = NULL;
+	struct rb_node *parent = NULL, *new_node;
 
 	while (*n) {
 		parent = *n;