Merge 3.18.51 into android-3.18

Changes in 3.18.51:
	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
	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
	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
	kvm: arm/arm64: Fix locking for kvm_free_stage2_pgd
	arm64: avoid returning from bad_mode
	clk: at91: usb: fix determine_rate prototype again
	gadgetfs: fix uninitialized variable in error handling
	dm bufio: hide bogus warning
	MIPS: Fix the build on jz4740 after removing the custom gpio.h
	perf: Avoid horrible stack usage
	fs/nfs: fix new compiler warning about boolean in switch
	iommu/vt-d: Remove unused variable
	mm/init: fix zone boundary creation
	net: ti: cpmac: Fix compiler warning due to type confusion
	MIPS: asm: compiler: Add new macros to set ISA and arch asm annotations
	nfsd: work around a gcc-5.1 warning
	Fix signed/unsigned pointer warning
	brcmfmac: avoid gcc-5.1 warning
	tty: nozomi: avoid a harmless gcc warning
	net: vxge: avoid unused function warnings
	misc: ioc4: simplify wave period measurement in clock_calibrate
	hostap: avoid uninitialized variable use in hfa384x_get_rid
	MIPS: MSP71xx: remove odd locking in PCI config space access code
	net: tulip: turn compile-time warning into dev_warn()
	mmc: sunxi: avoid invalid pointer calculation
	gfs2: avoid uninitialized variable warning
	btrfs: fix state->private cast on 32 bit machines
	ARM: 8296/1: cache-l2x0: clean up aurora cache handling
	aic94xx: Skip reading user settings if flash is not found
	MIPS: ralink: Cosmetic change to prom_init().
	kconfig: tinyconfig: provide whole choice blocks to avoid warnings
	ARM: 8383/1: nommu: avoid deprecated source register on mov
	xc2028: avoid use after free
	vfio/pci: Fix integer overflows, bitmask check
	staging/android/ion : fix a race condition in the ion driver
	ping: implement proper locking
	Linux 3.18.51

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