rawmidi: query: allow caller to take ownership of file descriptor for control charact...

rawmidi: query: allow caller to take ownership of file descriptor for control character device

In design of ALSA rawmidi interface, ALSA control interface has important
function to some operations. The alsarawmidi library has an internal
helper function to operate control character device. The helper function
closes file descriptor to the control character device before returning
to caller, however it's inconvenient to some operations.

This commit allows the caller to take ownership for opened file descriptor
of control character device.

Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>