qemu: split qemuDomainMemoryStats into internal and external functions
qemu: split qemuDomainMemoryStats into internal and external functions

Is necessary to call it from other contexts, such as qemuDomainGetStatsBalloon.

Signed-off-by: Derbyshev Dmitry <e4b949f9a1cd7cdc6d168bfa4092e31d260336d9@virtuozzo.com>

jardasgit/libvirt,jardasgit/libvirt,VenkatDatta/libvirt,andreabolognani/libvirt,nertpinx/libvirt,eskultety/libvirt,andreabolognani/libvirt,eskultety/libvirt,zippy2/libvirt,olafhering/libvirt,jardasgit/libvirt,nertpinx/libvirt,olafhering/libvirt,eskultety/libvirt,fabianfreyer/libvirt,VenkatDatta/libvirt,nertpinx/libvirt,eskultety/libvirt,jfehlig/libvirt,nertpinx/libvirt,VenkatDatta/libvirt,olafhering/libvirt,VenkatDatta/libvirt,andreabolognani/libvirt,taget/libvirt,datto/libvirt,zippy2/libvirt,libvirt/libvirt,olafhering/libvirt,taget/libvirt,taget/libvirt,andreabolognani/libvirt,crobinso/libvirt,datto/libvirt,jfehlig/libvirt,datto/libvirt,datto/libvirt,libvirt/libvirt,crobinso/libvirt,crobinso/libvirt,fabianfreyer/libvirt,fabianfreyer/libvirt,nertpinx/libvirt,zippy2/libvirt,crobinso/libvirt,VenkatDatta/libvirt,libvirt/libvirt,jardasgit/libvirt,zippy2/libvirt,taget/libvirt,eskultety/libvirt,jfehlig/libvirt,datto/libvirt,taget/libvirt,fabianfreyer/libvirt,andreabolognani/libvirt,libvirt/libvirt,fabianfreyer/libvirt,jfehlig/libvirt,jardasgit/libvirt