Fail Huion tablet interface enabling and probing, if parameter retrieval
fails. Move the main code path out of the else block accordingly.

This should prevent devices appearing in a half-working state due to
original report descriptor being used, simplifying diagnostics. This
also makes it easier to add cleanup in later commits, as error handling
is simplified.
Signed-off-by: Nikolai Kondrashov <spbnick@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>