virhostdev.h: remove ATTRIBUTE_NONNULL from oldStateDir
virhostdev.h: remove ATTRIBUTE_NONNULL from oldStateDir

In libxl driver oldStateDir is NULL when calling
virHostdevReAttachDomainHostdevs. This is allowed.
Remove ATTRIBUTE_NONNULL setting from oldStateDir.

Introduced by commit 6225cb3.

Signed-off-by: Chunyan Liu <699809cfcad49bea8cea68d656dfc4a832feaf7a@suse.com>
Signed-off-by: Ján Tomko <4cab11cfb98d3c937327354a78eb07dbb6ee2bc6@redhat.com>

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