qemu: Alter error path cleanup for qemuDomainAttachMemory
qemu: Alter error path cleanup for qemuDomainAttachMemory

A recent adjustment to qemuDomainAttachRNGDevice to properly cleanup
the props object after a qemuMonitorAddObject also would affect this
code. Alter the cleanup to be similar to RNG changes.

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