USB: io_ti: check firmware version before updating

USB: io_ti: check firmware version before updating

commit 0827a9ff2bbcbb03c33f1a6eb283fe051059482c upstream.

If we can't read the firmware for a device from the disk, and yet the
device already has a valid firmware image in it, we don't want to
replace the firmware with something invalid.  So check the version
number to be less than the current one to verify this is the correct
thing to do.

Reported-by: Chris Beauchamp <chris@chillibean.tv>
Tested-by: Chris Beauchamp <chris@chillibean.tv>
Cc: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>