winhttp: Fix invalid reads with tracing on (Valgrind).

Signed-off-by: Hans Leidekker <hans@codeweavers.com>
Signed-off-by: Alexandre Julliard <julliard@winehq.org>

dlls/winhttp/request.c

diff --git a/dlls/winhttp/request.c b/dlls/winhttp/request.c
index a355887..96a2c91 100644
--- a/dlls/winhttp/request.c
+++ b/dlls/winhttp/request.c
@@ -519,7 +519,7 @@
     BOOL ret;
     request_t *request;
 
-    TRACE("%p, %s, 0x%x, 0x%08x\n", hrequest, debugstr_w(headers), len, flags);
+    TRACE("%p, %s, %u, 0x%08x\n", hrequest, debugstr_wn(headers, len), len, flags);
 
     if (!headers || !len)
     {
@@ -2172,8 +2172,8 @@
     BOOL ret;
     request_t *request;
 
-    TRACE("%p, %s, 0x%x, %u, %u, %lx\n",
-          hrequest, debugstr_w(headers), headers_len, optional_len, total_len, context);
+    TRACE("%p, %s, %u, %u, %u, %lx\n", hrequest, debugstr_wn(headers, headers_len), headers_len, optional_len,
+          total_len, context);
 
     if (!(request = (request_t *)grab_object( hrequest )))
     {