Fix race condition in qemuGetProcessInfo
Fix race condition in qemuGetProcessInfo

There is a race condition between the fopen and fscanf calls
in qemuGetProcessInfo. If fopen succeeds, there is a small
possibility that the file no longer exists before reading from it.
Now, if either fopen or fscanf calls fail, the function will behave
just as only fopen had failed.

Fixes https://bugzilla.redhat.com/show_bug.cgi?id=1169055

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

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