linux_usbfs: Fix exit crash on Android In commit "89b810ec Android: Add option LIBUSB_OPTION_WEAK_AUTHORITY to support used in apk", we should also check weak_authority when exiting the backend. [dickens] Fixed whitespace Closes #842 Signed-off-by: Mark Kuo <starryalley@gmail.com> Signed-off-by: Chris Dickens <christopher.a.dickens@gmail.com>