Merge 4.9.25 into android-4.9

Changes in 4.9.25:
	KEYS: Disallow keyrings beginning with '.' to be joined as session keyrings
	KEYS: Change the name of the dead type to ".dead" to prevent user access
	KEYS: fix keyctl_set_reqkey_keyring() to not leak thread keyrings
	tracing: Allocate the snapshot buffer before enabling probe
	ring-buffer: Have ring_buffer_iter_empty() return true when empty
	mm: prevent NR_ISOLATE_* stats from going negative
	cifs: Do not send echoes before Negotiate is complete
	CIFS: remove bad_network_name flag
	s390/mm: fix CMMA vs KSM vs others
	Input: elantech - add Fujitsu Lifebook E547 to force crc_enabled
	ACPI / power: Avoid maybe-uninitialized warning
	mmc: sdhci-esdhc-imx: increase the pad I/O drive strength for DDR50 card
	ubifs: Fix RENAME_WHITEOUT support
	ubifs: Fix O_TMPFILE corner case in ubifs_link()
	mac80211: reject ToDS broadcast data frames
	mac80211: fix MU-MIMO follow-MAC mode
	ubi/upd: Always flush after prepared for an update
	powerpc/kprobe: Fix oops when kprobed on 'stdu' instruction
	x86/mce/AMD: Give a name to MCA bank 3 when accessed with legacy MSRs
	x86/mce: Make the MCE notifier a blocking one
	device-dax: switch to srcu, fix rcu_read_lock() vs pte allocation
	Linux 4.9.25

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