staging: unisys: fix some debugfs output

When we removed the ERRDEV() macro we made a small mistake so now it
doesn't print the "Virtual PCI devices" section header.

Fixes: 0aca7844 ('staging: unisys: remove ERRDEV macros')
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>