bcachefs: remove redundant variable tmp

The variable tmp is being assigned a value but it isn't being
read afterwards. The assignment is redundant and so tmp can be
removed.

Cleans up clang scan build warning:
warning: Although the value stored to 'ret' is used in the enclosing
expression, the value is never actually read from 'ret'
[deadcode.DeadStores]

Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

Author: ColinIanKing

fs/bcachefs/rebalance.c

@@ -385,16 +385,14 @@ static int bch2_rebalance_thread(void *arg)
 	struct bch_fs *c = arg;
 	struct bch_fs_rebalance *r = &c->rebalance;
 	struct moving_context ctxt;
-	int ret;
 
 	set_freezable();
 
 	bch2_moving_ctxt_init(&ctxt, c, NULL, &r->work_stats,
 			      writepoint_ptr(&c->rebalance_write_point),
 			      true);
 
-	while (!kthread_should_stop() &&
-	       !(ret = do_rebalance(&ctxt)))
+	while (!kthread_should_stop() && !do_rebalance(&ctxt))
 		;
 
 	bch2_moving_ctxt_exit(&ctxt);