Pull xen fixes from Juergen Gross:
- some fixes of kmalloc() flags
- one fix of the xenbus driver
- an update of the pv sound driver interface needed for a driver which
will go through the sound tree
* tag 'for-linus-4.17-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
xen: xenbus_dev_frontend: Really return response string
xen/sndif: Sync up with the canonical definition in Xen
xen: xen-pciback: Replace GFP_ATOMIC with GFP_KERNEL in pcistub_reg_add
xen: xen-pciback: Replace GFP_ATOMIC with GFP_KERNEL in xen_pcibk_config_quirks_init
xen: xen-pciback: Replace GFP_ATOMIC with GFP_KERNEL in pcistub_device_alloc
xen: xen-pciback: Replace GFP_ATOMIC with GFP_KERNEL in pcistub_init_device
xen: xen-pciback: Replace GFP_ATOMIC with GFP_KERNEL in pcistub_probe