virsh: improve the error for wrong memtune parameters
virsh: improve the error for wrong memtune parameters

When set guest memory with a invalid parameter of --soft-limit,
it posts weird error:

$ virsh memtune r7 --hard-limit 20417224 --soft-limit 9007199254740992 \
  --swap-hard-limit 35417224
error: Unable to parse integer parameter 'NAME

Change it to

error: Unable to parse integer parameter soft-limit

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1211550
Signed-off-by: Shanzhi Yu <98ab354c31cd9189e8ce8ab338c511d403e2f789@redhat.com>
Signed-off-by: Ján Tomko <4cab11cfb98d3c937327354a78eb07dbb6ee2bc6@redhat.com>

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