The `ref_transaction_add_update()` creates the `ref_update` struct. To
facilitate addition of reflogs in the next commit, the function needs to
accommodate setting the `committer_info` field in the struct. So modify
the function to also take `committer_info` as an argument and set it
accordingly.

Signed-off-by: Karthik Nayak <redacted>
---
 refs.c                  |  7 +++++--
 refs/files-backend.c    | 14 ++++++++------
 refs/refs-internal.h    |  1 +
 refs/reftable-backend.c |  6 ++++--
 4 files changed, 18 insertions(+), 10 deletions(-)

diff --git a/refs.c b/refs.c
index 9c9f4940c60d3cdd34ce8f1e668d17b9da3cd801..782bf1090af65196263a3c35ed18d878bb4f2967 100644
--- a/refs.c
+++ b/refs.c

@@ -1166,6 +1166,7 @@ struct ref_update *ref_transaction_add_update(
 		const struct object_id *new_oid,
 		const struct object_id *old_oid,
 		const char *new_target, const char *old_target,
+		const char *committer_info,
 		const char *msg)
 {
 	struct ref_update *update;

@@ -1190,8 +1191,10 @@ struct ref_update *ref_transaction_add_update(
 		oidcpy(&update->new_oid, new_oid);
 	if ((flags & REF_HAVE_OLD) && old_oid)
 		oidcpy(&update->old_oid, old_oid);
-	if (!(flags & REF_SKIP_CREATE_REFLOG))
+	if (!(flags & REF_SKIP_CREATE_REFLOG)) {
+		update->committer_info = xstrdup_or_null(committer_info);