usb: usbip tool: Fix get_nports()

The commit 0775a9cbc694e8c72 ("usbip: vhci extension: modifications
to vhci driver") introduced multiple controllers, and nports as a sys
file, and claimed to read the nports from it, but it didn't.

In addition, the get_nports() has been so wrong that even with 8 port
lines for instance, it gets 7 (I am guessing it is due to a '\n' mess).
Nevertheless, we fix it by reading the nports attribute.

Reviewed-by: Krzysztof Opasiak <k.opasiak@samsung.com>
Signed-off-by: Yuyang Du <yuyang.du@intel.com>
Acked-by: Shuah Khan <shuahkh@osg.samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

tools/usb/usbip/libsrc/vhci_driver.c

@@ -123,33 +123,15 @@ static int refresh_imported_device_list(void)
 
 static int get_nports(void)
 {
-	char *c;
-	int nports = 0;
-	const char *attr_status;
+	const char *attr_nports;
 
-	attr_status = udev_device_get_sysattr_value(vhci_driver->hc_device,
-					       "status");
-	if (!attr_status) {
-		err("udev_device_get_sysattr_value failed");
+	attr_nports = udev_device_get_sysattr_value(vhci_driver->hc_device, "nports");
+	if (!attr_nports) {
+		err("udev_device_get_sysattr_value nports failed");
 		return -1;
 	}
 
-	/* skip a header line */
-	c = strchr(attr_status, '\n');
-	if (!c)
-		return 0;
-	c++;
-
-	while (*c != '\0') {
-		/* go to the next line */
-		c = strchr(c, '\n');
-		if (!c)
-			return nports;
-		c++;
-		nports += 1;
-	}
-
-	return nports;
+	return (int)strtoul(attr_nports, NULL, 10);
 }
 
 /*