refs: use `size_t` indexes when iterating over ref transaction updates

Eliminate any chance of integer overflow on platforms where the two
types have different sizes.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 1 insertions, 1 deletions

diff --git a/refs.c b/refs.c
index 8494b1f20d..71139ba74e 100644
--- a/refs.c
+++ b/refs.c
@@ -848,7 +848,7 @@ struct ref_transaction *ref_transaction_begin(struct strbuf *err)
 
 void ref_transaction_free(struct ref_transaction *transaction)
 {
-	int i;
+	size_t i;
 
 	if (!transaction)
 		return;