Use uint64_t instead of u64 in put_dec()

Use the correct type required by do_div().

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/lib/vsprintf.c b/lib/vsprintf.c
index 7ec758e..b585713 100644
--- a/lib/vsprintf.c
+++ b/lib/vsprintf.c
@@ -270,7 +270,7 @@
 	return buf;
 }
 /* No inlining helps gcc to use registers better */
-static noinline char *put_dec(char *buf, u64 num)
+static noinline char *put_dec(char *buf, uint64_t num)
 {
 	while (1) {
 		unsigned rem;