usb: Attempt detaching kernel driver

In the event that the kernel have some other driver attached to the
device the attempt claim of the interface will fail.

Lost in the libusb conversion was a call to USBDEVFS_DISCONNECT to first
detach any such drivers. Reintroduce this by invoking
libusb_detach_kernel_driver().

As with some other libusb functions there are multiple return values
denoting "success", so rely on libusb_claim_interface() to catch the
actual errors.

Reported-by: Maxim Akristiniy
Suggested-by: Maxim Akristiniy
Signed-off-by: Bjorn Andersson <[email protected]>

usb.c

@@ -126,6 +126,8 @@ static int qdl_try_open(libusb_device *dev, struct qdl_device *qdl, const char *
 			continue;
 		}
 
+		libusb_detach_kernel_driver(handle, ifc->bInterfaceNumber);
+
 		ret = libusb_claim_interface(handle, ifc->bInterfaceNumber);
 		if (ret < 0) {
 			warnx("failed to claim USB interface");