[PATCH 7/9] btrfs-progs: Fix Wmaybe-uninitialized warning

[Qu Wenruo]

The only location is the following code:

        int level = path->lowest_level + 1;
        BUG_ON(path->lowest_level + 1 >= BTRFS_MAX_LEVEL);
        while(level < BTRFS_MAX_LEVEL) {
                slot = path->slots[level] + 1;
                ...
        }
        path->slots[level] = slot;

Again, it's the stupid compiler needs some hint for the fact that
we will always enter the while loop for at least once, thus @slot should
always be initialized.

Fix it by assign level after the BUG_ON(), so the stupid compiler knows
we will always go into the while loop.

Signed-off-by: Qu Wenruo <w...@suse.com>
---
 ctree.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/ctree.c b/ctree.c
index 46e2ccedc0bf..9c9cb0dfdbf2 100644
--- a/ctree.c
+++ b/ctree.c
@@ -2961,11 +2961,12 @@ int btrfs_next_sibling_tree_block(struct btrfs_fs_info 
*fs_info,
                                  struct btrfs_path *path)
 {
        int slot;
-       int level = path->lowest_level + 1;
+       int level;
        struct extent_buffer *c;
        struct extent_buffer *next = NULL;
 
        BUG_ON(path->lowest_level + 1 >= BTRFS_MAX_LEVEL);
+       level = path->lowest_level + 1;
        while(level < BTRFS_MAX_LEVEL) {
                if (!path->nodes[level])
                        return 1;
-- 
2.19.1