xhci: Redundant check in xhci_check_args for xhci->devs

The xhci_hcd->devs is an array of pointers rather than pointer to pointer.
Hence this check is not required.

Signed-off-by: Sifram Rajas &lt;Sifram Rajas <sifram.rajas@gmail.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>