Merge 4.9.20 into android-4.9

Changes in 4.9.20:
	xfrm: policy: init locks early
	xfrm_user: validate XFRM_MSG_NEWAE XFRMA_REPLAY_ESN_VAL replay_window
	xfrm_user: validate XFRM_MSG_NEWAE incoming ESN size harder
	KVM: x86: cleanup the page tracking SRCU instance
	virtio_balloon: init 1st buffer in stats vq
	pinctrl: qcom: Don't clear status bit on irq_unmask
	c6x/ptrace: Remove useless PTRACE_SETREGSET implementation
	h8300/ptrace: Fix incorrect register transfer count
	mips/ptrace: Preserve previous registers for short regset write
	sparc/ptrace: Preserve previous registers for short regset write
	metag/ptrace: Preserve previous registers for short regset write
	metag/ptrace: Provide default TXSTATUS for short NT_PRSTATUS
	metag/ptrace: Reject partial NT_METAG_RPIPE writes
	fscrypt: remove broken support for detecting keyring key revocation
	sched/rt: Add a missing rescheduling point
	usb: musb: fix possible spinlock deadlock
	Linux 4.9.20

Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>