usb: hub_activate kill an 'else'

Remove a few extra lines and make it clear that all implementations
disable the port by sharing the same line of code.

Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>