usbd: Do not join the thread pool

Work around for the following crash:
02-08 05:34:20.968  root   990   990 F DEBUG   :     #00 pc 000000000001447c  /system/lib64/libhwbinder.so (android::hardware::IPCThreadState::joinThreadPool(bool)+28)
02-08 05:34:20.968  root   990   990 F DEBUG   :     #01 pc 000000000001c174  /system/lib64/libhwbinder.so (android::hardware::PoolThread::threadLoop()+24)
02-08 05:34:20.968  root   990   990 F DEBUG   :     #02 pc 000000000000f934  /system/lib64/libutils.so (android::Thread::_threadLoop(void*)+280)
02-08 05:34:20.968  root   990   990 F DEBUG   :     #03 pc 00000000000821e0  /system/lib64/libc.so (__pthread_start(void*)+36)
02-08 05:34:20.968  root   990   990 F DEBUG   :     #04 pc 0000000000023178  /system/lib64/libc.so (__start_thread+68)

Bug: 117470462
Change-Id: I1e8f28a7d0f3041d9be8138a3dc9ed9c74419f91
1 file changed