posix_devctl() should return the errno directly not -1 and set errno

[Joel Sherrill]

The RTEMS implementation of posix_devctl() from POSIX 1003.26 does not return error codes as required by the standard.

"Upon successful completion, posix_devctl() shall return zero; otherwise an error number shall be returned to indicate the error. The value returned via the dev_info_ptr argument is driver dependent."

It should return the errno value and not -1 and set the errno variable. The current behavior is wrong but understandable because the implementation is a wrapper for close() and ioctl() which do set errno and return -1.

[Ryan Long <ryan.long@…>]

In e9712e78/rtems:

pxcdevctl: Adjust for standard (5 branch)

psxdevctl is supposed to return the value in errno. Before, it was
returning -1 and setting errno. Changed the tests to reflect these
changes. Added code from RRADE's posix_devctl.c.

Closes #4505