qemu: virtiofs: shorten pid filename
qemu: virtiofs: shorten pid filename

There is no need to repeat the shortName, since it's
already present in the directory path.

Also use just 'fs' instead of 'virtiofsd'.

https://bugzilla.redhat.com/show_bug.cgi?id=1816577

Signed-off-by: Ján Tomko <4cab11cfb98d3c937327354a78eb07dbb6ee2bc6@redhat.com>
Suggested-by: Andrea Bolognani <3ada0bee826c753786fdbba72243dfba997094cf@redhat.com>
Reviewed-by: Michal Privoznik <83d82aaba2eed257f4814b0c239c260c4caaadf0@redhat.com>

crobinso/libvirt,fabianfreyer/libvirt,olafhering/libvirt,jardasgit/libvirt,jfehlig/libvirt,crobinso/libvirt,jardasgit/libvirt,olafhering/libvirt,jardasgit/libvirt,jardasgit/libvirt,libvirt/libvirt,zippy2/libvirt,jfehlig/libvirt,libvirt/libvirt,nertpinx/libvirt,olafhering/libvirt,libvirt/libvirt,nertpinx/libvirt,fabianfreyer/libvirt,crobinso/libvirt,fabianfreyer/libvirt,jardasgit/libvirt,nertpinx/libvirt,zippy2/libvirt,crobinso/libvirt,fabianfreyer/libvirt,jfehlig/libvirt,olafhering/libvirt,nertpinx/libvirt,fabianfreyer/libvirt,libvirt/libvirt,zippy2/libvirt,zippy2/libvirt,jfehlig/libvirt,nertpinx/libvirt