*.c static functions: add missing __attribute__((format))

Add missing __attribute__((format)) function attributes to various
"static" functions that take printf arguments.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

server-info.c

@@ -27,6 +27,7 @@ static int uic_is_stale(const struct update_info_ctx *uic)
 	return uic->old_fp == NULL;
 }
 
+__attribute__((format (printf, 2, 3)))
 static int uic_printf(struct update_info_ctx *uic, const char *fmt, ...)
 {
 	va_list ap;