Input: powermate - fix oops with malicious USB descriptors
The powermate driver expects at least one valid USB endpoint in its
probe function. If given malicious descriptors that specify 0 for
the number of endpoints, it will crash. Validate the number of
endpoints on the interface before using them.
The full report for this issue can be found here:
http://seclists.org/bugtraq/2016/Mar/85