ALSA: seq: fix to copy from/to user space

When checking value of request for copy operation, current implementation
compares shifted value to macros, while these macros are already shifted.
As a result, it never performs to copy from/to user space.

This commit fixes the bug.

Fixes: 8ce8eb60

('ALSA: seq: add an alternative way to handle ioctl requests'
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>