do not fail on EACCES when trying to open() evdevs

[tempura-san]

(hopefully) improved fix of problem described in #431

[tempura-san]

The second commit could be omitted. I tend to finalise every statement, but the definition of PRINT_ERROR_ERRNO() allows the semicolon to be optional as it is already present in the macro.

[matlo]

Are you sure the errno value was EACCES = "Permission denied"?

A similar issue was reported on the forum: https://forum.gimx.fr/viewtopic.php?f=5&t=1996
In this case errno was EPERM = "Operation not permitted".

I think I will make all errors to be ignored (but still reported in the messages). Someone may want to apply different ownership and permissions on devices.

[tempura-san]

I will check the error code once I have the computer back at home - likely tomorrow.

[matlo]

This should be fixed by #437.

[tempura-san]

@matlo I messed it up. In fact it was EPERM (=Operation not permitted). 😓 I have the German locale active, so it was a bit misleading. Sorry for the confusion.
The latest change #437 fixes the issue for me. The two offending devices (/dev/input/event9 and /dev/input/js0) are listed in the console failing with EPERM, but GIMX starts nonetheless.
So thank you for your help and support!