Re: [libvirt] [PATCHv2] util: recognize SMB/CIFS filesystems as shared

This should resolve: https://bugzilla.redhat.com/show_bug.cgi?id=1012085 libvirt previously recognized NFS, GFS2, OCFS2, and AFS filesystems as "shared", and thus eligible for exceptions to certain rules/actions about chowning image files before handing them off to a guest. This patch widens the definition of "shared filesystem" to include SMB and CIFS filesystems (aka "Windows file sharing"); both of these use the same protocol, but different drivers so there are different magic numbers for each. --- Change from V1 - also check for CIFS_SUPER_MAGIC, not just SMB_SUPER_MAGIC.