maint: fix comma style issues: remaining code
    
    Most of our code base uses space after comma but not before;
    fix the remaining uses before adding a syntax check.
    
    * src/network/bridge_driver.c: Consistently use commas.
    * src/node_device/node_device_hal.c: Likewise.
    * src/node_device/node_device_udev.c: Likewise.
    * src/storage/storage_backend_rbd.c: Likewise.
    
    Signed-off-by: Eric Blake <eblake@redhat.com>