maint: fix comma style issues: util
    
    Most of our code base uses space after comma but not before;
    fix the remaining uses before adding a syntax check.
    
    * src/util/vircommand.c: Consistently use commas.
    * src/util/virlog.c: Likewise.
    * src/util/virnetdevbandwidth.c: Likewise.
    * src/util/virnetdevmacvlan.c: Likewise.
    * src/util/virnetdevvportprofile.c: Likewise.
    * src/util/virnetlink.c: Likewise.
    * src/util/virpci.c: Likewise.
    * src/util/virsysinfo.c: Likewise.
    * src/util/virusb.c: Likewise.
    
    Signed-off-by: Eric Blake <eblake@redhat.com>