staging: unisys: virtpci: Adjust lines to contain a maximum of 80 characters

Update delete_all_virt function definition to two lines so each line is less than 80
characters long.

Move comments on virtpci_device_add function parameters to a header block to contain
each line to 80 characters.

Signed-off-by: Bryan Thompson <bryan.thompson@unisys.com>
Signed-off-by: Benjamin Romer <benjamin.romer@unisys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>