wbt-200: Fix MSVC warning (signed/unsigned mismatch).

diff --git a/gpsbabel/wbt-200.c b/gpsbabel/wbt-200.c
index 1acbe2448d04ea5a61e59f9e30133db2f24e75e3..7884505624e4bce191dfd837b68db21c80007ab4 100644 (file)
--- a/gpsbabel/wbt-200.c
+++ b/gpsbabel/wbt-200.c
@@ -719,7 +719,7 @@ static void wbt200_data_read(void) {
     state_empty(&st);
 }
 
-static int all_null(const void *buf, size_t len) {
+static int all_null(const void *buf, const int len) {
     const char *bp = buf;
     int i;