staging: unisys: fix checkpatch checks for structs in virthba.c

This patch fixes a couple small issues reported by the checkpatch script:
  Adds a blank line after a struct definition.
  Removes unnecessary parentheses surrounding a dereference of a struct member.

Signed-off-by: Ken Depro <kenneth.depro@unisys.com>
Signed-off-by: Benjamin Romer <benjamin.romer@unisys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>