usb: Make usb_hcd_pci_probe labels more descriptive.

usb: Make usb_hcd_pci_probe labels more descriptive.

Make the labels for the goto statements in usb_hcd_pci_probe()
describe the cleanup they do, rather than being numbered err[1-4].
This makes it easier to add error handling later.

The error handling for this function looks a little fishy, since
set_hs_companion() isn't called until the very end of the function, and
clear_hs_companion() is called if this function fails earlier than that.
But it should be harmless to clear a NULL pointer, so leave the error
handling as-is.

Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>