fftools/ffmpeg_opt: drop HAS_ARG from auto{scale,rotate}

It causes those options to be parsed as either
* -autofoo 0/1 (with an argument)
* -noautofoo   (without an argument)
This is unnecessary, confusing, and against the documentation; these are
also the only two bool options that take an argument.

This should not affect the users, as these options are on by default,
and are supposed to be used as -nofoo per the documentation.

fftools/ffmpeg_opt.c

@@ -1743,11 +1743,9 @@ const OptionDef options[] = {
         "select output format used with HW accelerated decoding", "format" },
     { "hwaccels",         OPT_EXIT,                                              { .func_arg = show_hwaccels },
         "show available HW acceleration methods" },
-    { "autorotate",       HAS_ARG | OPT_BOOL | OPT_SPEC |
-                          OPT_EXPERT | OPT_INPUT,                                { .off = OFFSET(autorotate) },
+    { "autorotate",       OPT_BOOL | OPT_SPEC | OPT_EXPERT | OPT_INPUT,          { .off = OFFSET(autorotate) },
         "automatically insert correct rotate filters" },
-    { "autoscale",        HAS_ARG | OPT_BOOL | OPT_SPEC |
-                          OPT_EXPERT | OPT_OUTPUT,                               { .off = OFFSET(autoscale) },
+    { "autoscale",        OPT_BOOL | OPT_SPEC | OPT_EXPERT | OPT_OUTPUT,         { .off = OFFSET(autoscale) },
         "automatically insert a scale filter at the end of the filter graph" },
     { "fix_sub_duration_heartbeat", OPT_VIDEO | OPT_BOOL | OPT_EXPERT |
                                     OPT_SPEC | OPT_OUTPUT,                       { .off = OFFSET(fix_sub_duration_heartbeat) },