Increase the size of REMOTE_MIGRATE_COOKIE_MAX to REMOTE_STRING_MAX
Increase the size of REMOTE_MIGRATE_COOKIE_MAX to REMOTE_STRING_MAX

During guest migration, if the domain xml is bigger than 16384 which is
easily possible for a guest with good number of disks, message encode fails
for xdr_remote_domain_migrate_perform3_ret().
So, Increase the COOKIE_MAX to STRING_MAX value.

Signed-off-by: Shivaprasad G Bhat <e3b9a78c646091ad1d0ec2b64f1b4414eea202d9@gmail.com>

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