tests: fix virpcitest with read-only srcdir
tests: fix virpcitest with read-only srcdir

'make distcheck' has been broken since commit 21685c9; basically,
it emulates the case of a read-only $(srcdir) (such as building
from a tarball exploded onto a CD-ROM), but we were creating our
fake pci device as a symlink into $(srcdir) and failing when that
requires opening the config file for writing:

 3) testVirPCIDeviceReset                                             ... libvirt:  error : Failed to open config space file '/sys/bus/pci/devices/0000:00:01.0/config': Permission denied

Fix it by copying rather than symlinking.

* tests/virpcimock.c (make_file): Add parameter to allow binary
creation; adjust all callers.
(pci_device_new_from_stub): Copy rather than symlink.

Signed-off-by: Eric Blake <a9da18479c871fe903d9590822cfe2629c6a4d11@redhat.com>

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