The structure returned by readdir is may be statically allocated.
Keeping a pointer to it is broken.
The LED path is generally not a directory, it's a link to a directory.
And even if it were a directory, that would tell nothing about the
caller's access permissions.
And then there is a lot of duplication between mraa_led_init and
mraa_led_init_raw.
This addresses that all.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
954b17ded4