Add a quirk for WORLDE easykey.25 MIDI keyboard (idVendor=0218,
idProduct=0401). The device reports that it has config string
descriptor at index 3, but when the system selects the configuration
and tries to get the description, it returns a -EPROTO error,
the communication restarts and this keeps repeating over and over again.
Not requesting the string descriptor makes the device work correctly.

Relevant info from Wireshark:

[...]

CONFIGURATION DESCRIPTOR
    bLength: 9
    bDescriptorType: 0x02 (CONFIGURATION)
    wTotalLength: 101
    bNumInterfaces: 2
    bConfigurationValue: 1
    iConfiguration: 3
    Configuration bmAttributes: 0xc0  SELF-POWERED  NO REMOTE-WAKEUP
        1... .... = Must be 1: Must be 1 for USB 1.1 and higher
        .1.. .... = Self-Powered: This device is SELF-POWERED
        ..0. .... = Remote Wakeup: This device does NOT support remote wakeup
    bMaxPower: 50  (100mA)

[...]

     45 0.369104       host                  2.38.0                USB      64     GET DESCRIPTOR Request STRING

[...]

URB setup
    bmRequestType: 0x80
        1... .... = Direction: Device-to-host
        .00. .... = Type: Standard (0x00)
        ...0 0000 = Recipient: Device (0x00)
    bRequest: GET DESCRIPTOR (6)
    Descriptor Index: 0x03
    bDescriptorType: 0x03
    Language Id: English (United States) (0x0409)
    wLength: 255

     46 0.369255       2.38.0                host                  USB      64     GET DESCRIPTOR Response STRING[Malformed Packet]

[...]

Frame 46: 64 bytes on wire (512 bits), 64 bytes captured (512 bits) on interface 0
USB URB
    [Source: 2.38.0]
    [Destination: host]
    URB id: 0xffff88021f62d480
    URB type: URB_COMPLETE ('C')
    URB transfer type: URB_CONTROL (0x02)
    Endpoint: 0x80, Direction: IN
    Device: 38
    URB bus id: 2
    Device setup request: not relevant ('-')
    Data: present (0)
    URB sec: 1484896277
    URB usec: 455031
    URB status: Protocol error (-EPROTO) (-71)
    URB length [bytes]: 0
    Data length [bytes]: 0
    [Request in: 45]
    [Time from request: 0.000151000 seconds]
    Unused Setup Header
    Interval: 0
    Start frame: 0
    Copy of Transfer Flags: 0x00000200
    Number of ISO descriptors: 0
[Malformed Packet: USB]
    [Expert Info (Error/Malformed): Malformed Packet (Exception occurred)]
        [Malformed Packet (Exception occurred)]
        [Severity level: Error]
        [Group: Malformed]
Signed-off-by: Lukáš Lalinský <lukas@oxygene.sk>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>