comedi: get rid of compat_alloc_user_space() mess in COMEDI_CHANINFO compat

Just take copy_from_user() out of do_chaninfo_ioctl() into the caller and
have compat_chaninfo() build a native version and pass it to do_chaninfo_ioctl()
directly.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Al Viro 2020-04-25 18:35:03 -04:00
commit 3fbfd2223a