cfg: Ignore return values of fopen_s functions.

cfg/std.cfg

@@ -947,7 +947,6 @@
                 const char *restrict filename,
                 const char *restrict mode); -->
   <function name="fopen_s">
-    <use-retval/>
     <noreturn>false</noreturn>
     <arg nr="1">
       <not-null/>

cfg/windows.cfg

@@ -2073,7 +2073,6 @@ HFONT CreateFont(
   </function>
   <!-- errno_t _wfopen_s(FILE** pFile, const wchar_t *filename, const wchar_t *mode); -->
   <function name="_wfopen_s,_tfopen_s">
-    <use-retval/>
     <noreturn>false</noreturn>
     <arg nr="1">
       <not-null/>