net: usb: Handle interface suspend properly

Upon interface suspend driver performs suspend on data channel
first and then on control channel. In case if suspend aborts
due to pending transfer on control channel, driver is not
undoing data channel suspend. This causes stall on data channel.
Fix the problem by performing suspend check on control channel
first. In this case if suspend aborts on control channel, driver
does not have to undo anything to abort interface suspend. Once
data channel suspend succeeds driver performs suspend on control
channel.

Signed-off-by: Hemant Kumar <hemantk@codeaurora.org>
Change-Id: I405b4797740e1b2aa67c6c28a2f3dcee0c196391