Fixed returned length for LB_GETTEXT.

diff --git a/controls/listbox.c b/controls/listbox.c
index 3e4d442..24920d7 100644
--- a/controls/listbox.c
+++ b/controls/listbox.c
@@ -762,7 +762,7 @@
         else
         {
             LPSTR buffer = (LPSTR)lParam;
-            return WideCharToMultiByte(CP_ACP, 0, descr->items[index].str, -1, buffer, 0x7FFFFFFF, NULL, NULL);
+            return WideCharToMultiByte(CP_ACP, 0, descr->items[index].str, -1, buffer, 0x7FFFFFFF, NULL, NULL) - 1;
         }
     } else {
         if (lParam)