[PATCH] Btrfs: use next_state in find_first_extent_bit

[Liu Bo]

As next_state() is already defined to get the next state, update us to use
the helper.

No functional changes.

Signed-off-by: Liu Bo <bo....@linux.alibaba.com>
---
 fs/btrfs/extent_io.c | 7 +------
 1 file changed, 1 insertion(+), 6 deletions(-)

diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index 628f1aef34b0..44397fa909c2 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -1424,20 +1424,15 @@ int find_first_extent_bit(struct extent_io_tree *tree, 
u64 start,
                          struct extent_state **cached_state)
 {
        struct extent_state *state;
-       struct rb_node *n;
        int ret = 1;
 
        spin_lock(&tree->lock);
        if (cached_state && *cached_state) {
                state = *cached_state;
                if (state->end == start - 1 && extent_state_in_tree(state)) {
-                       n = rb_next(&state->rb_node);
-                       while (n) {
-                               state = rb_entry(n, struct extent_state,
-                                                rb_node);
+                       while ((state = next_state(state)) != NULL) {
                                if (state->state & bits)
                                        goto got_it;
-                               n = rb_next(n);
                        }
                        free_extent_state(*cached_state);
                        *cached_state = NULL;
-- 
1.8.3.1