qemu fail to parse command line with "-pcidevice B:D.F"

[xudong]

Host OS:ia32e
Guest OS :32e and pae
kvm.git Commit:a63e16c655f9e68d49d6fae4275ffda16b1888b2
qemu-kvm Commit:97011c7fce92f8c0928c9e94e9896f0dca1bdeb9
Host Kernel Version:2.6.35-rc3
Hardware:Gulftown-HEDT

Bug detailed description:
--------------------------
when use command "qemu-system_x86 -smp 2 -m 1024 -hda /path/to/img -pcidevice
host=00:19.0" to assign a nic to guest, guest cannot boot up, and display error
message:
qemu-system-x86_64: Parameter 'id' expects an identifier
Identifiers consist of letters, digits, '-', '.', '_', starting with a letter.
pcidevice argument parse error; please check the help text for usage
Could not add assigned device host=00:19.0

It's caused by commit: b560a9ab9be06afcbb78b3791ab836dad208a239. It took "00:19.0" alike form as illegal.

Reproduce steps:
----------------
1. boot up into host
2. use pcistub hide a nic: #sh pcistub.sh -h 00:19.0
3. when use command "qemu-system_x86 -smp 2 -m 1024 -hda /path/to/img
-pcidevice host=00:19.0" to assign a nic to guest

[xudong (xudong-hao)]

Now we use new command to do VT-d device assignment:
"qemu-system_x86 -smp 2 -m 1024 -hda /path/to/img -device pci-assign,host=00:19.0"