In FreeBSD's errno.h ERESTART is not defined by default, only when the
user requests the pseudo-errors returned inside the kernel to be
enabled. As a result the block where drmCommandWriteRead is
called returns compile error. Defined _WANT_KERNEL_ERRNO to fix it (see
FreeBSD's /usr/include/errno.h)
Signed-off-by: Eleni Maria Stea <elene.mst@gmail.com>
Reviewed-by: Eric Engestrom <eric@engestrom.ch>