staging: unisys: visorbus: Clean up vmcall address function.

The function vmcall address needed to be cleaned up. The structure
vmcall_controlvm_addr was not needed so it was removed and was replaced
with vmcall_io_controlvm_addr_params since it needs to be allocated on the
heap for DMA access.

With the structure removed and the fields as local variables, it helped
clean up the formatting of the function.

Signed-off-by: David Kershner <david.kershner@unisys.com>
Reviewed-by: Tim Sell <timothy.sell@unisys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>