usb: host: xhci: drop redundant checks

usb: host: xhci: drop redundant checks

In xhci_endpoint_{disable|reset}() the expression '&vdev->eps[ep_index]'
just cannot be NULL, so the checks have no sense at all...

Found by Linux Verification Center (linuxtesting.org) with the SVACE static
analysis tool.

Signed-off-by: Sergey Shtylyov <s.shtylyov@omp.ru>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20220216095153.1303105-9-mathias.nyman@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>