Pull xen fixes from Juergen Gross:
"Only several small fixes and cleanups this time"
* tag 'for-linus-4.20a-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
xen: drop writing error messages to xenstore
xen/pvh: don't try to unplug emulated devices
add myself as reviewer for Xen support in Linux
xen: remove redundant 'default n' from Kconfig
xen/balloon: Support xend-based toolstack
xen/pvh: increase early stack size
xen: make xen_qlock_wait() nestable
xen: fix race in xen_qlock_wait()
xen/balloon: Grammar s/Is it/It is/
xen: Make XEN_BACKEND selectable by DomU