bcachefs: eytzinger_for_each() declares loop iter

Signed-off-by: Kent Overstreet <[e-mail]>

fs/bcachefs/bset.c

···
 {
 	struct bkey_packed *prev = NULL, *k = btree_bkey_first(b, t);
 	struct bkey_i min_key, max_key;
-	unsigned j, cacheline = 1;
+	unsigned cacheline = 1;
 
 	t->size = min(bkey_to_cacheline(b, t, btree_bkey_last(b, t)),
 		      bset_ro_tree_capacity(b, t));

fs/bcachefs/eytzinger.h

···
 }
 
 #define eytzinger1_for_each(_i, _size)			\
-	for ((_i) = eytzinger1_first((_size));		\
+	for (unsigned (_i) = eytzinger1_first((_size));	\
 	     (_i) != 0;					\
 	     (_i) = eytzinger1_next((_i), (_size)))
 
···
 }
 
 #define eytzinger0_for_each(_i, _size)			\
-	for ((_i) = eytzinger0_first((_size));		\
+	for (unsigned (_i) = eytzinger0_first((_size));	\
 	     (_i) != -1;				\
 	     (_i) = eytzinger0_next((_i), (_size)))