staging: unisys: refactor create_device()

OK, lets clean up this messy function. The entire thing is reflowed so spacing
and indentation is correct. Tests that created extra indentation were swapped
for equivalent negative tests that did not create extra indentation. Use of
cmp_uuid_le() were fixed to test specifically for the zero case, and not to
lazily use !cmp_uuid_le(). CamelCase local variable names were fixed:

busNo => bus_no
devNo => dev_no
minSize => min_size
pReqHandler => req_handler
Away => cleanup

Finally, the struct guest_msgs cmd declaration was moved to the beginning of
the function, and cringing and wincing at the function was significantly
reduced.
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>