qemu: driver: Reuse qemuDomainBlocksStatsGather in qemuDomainGetBlockInfo
qemu: driver: Reuse qemuDomainBlocksStatsGather in qemuDomainGetBlockInfo

Allow updating capacity for the block devices returned by
qemuDomainBlocksStatsGather and replace the open-coded call to
qemuMonitorGetAllBlockStatsInfo by the helper.

Signed-off-by: Peter Krempa <2cf5c04c61aa466e4a47bfedc747d17279c72ffc@redhat.com>
Reviewed-by: Ján Tomko <4cab11cfb98d3c937327354a78eb07dbb6ee2bc6@redhat.com>

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