usb: mbim: Fixed alternate interface request
usb: mbim: Fixed alternate interface request

To pass USBCV chapter 9 tests, alt interface request must
return the last alt interface number set by host.
mbim get_alt now returns the correct alternate interface number.

Change-Id: Ibb9e7b0e118c3425f2c80d86ebacfe670a13a9be
CRs-Fixed: 427504
Signed-off-by: Bar Weiner <82101f7d77aed15ad40cd904b803b43d89dad24c@codeaurora.org>

TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas