wldap32: Use return value of sprintf() instead of hardcoding the number of written characters.

dlls/wldap32/misc.c

@@ -226,10 +226,7 @@ static void escape_filter_element( PCHAR src, ULONG srclen, PCHAR dst )
             (src[i] >= 'a' && src[i] <= 'z'))
             *d++ = src[i];
         else
-        {
-            sprintf( d, fmt, (unsigned char)src[i] );
-            d += 3;
-        }
+            d += sprintf( d, fmt, (unsigned char)src[i] );
     }
     *++d = 0;
 }