OpenAFS mock builds should not rely on running kernel version

[ezyang]

We currently test for what kernel to build OpenAFS against using:

kernvers = $(shell uname -r | sed "s/\(.*\)[.].*/\1/")

This is not ideal since it means we need to manually frob that line or reboot into a newer kernel before we can rebuild, say, OpenAFS. Do something more intelligent, like build against the version of the kernel that our repositories give us.

[andersk]

No manual frobbing is required, since all Makefile variables can be overridden on the command line (unless the variable was itself declared with the override directive):

make openafs-kernel kernvers=2.6.30.10-105.2.23.scripts.1653M.fc11

This is documented in server/doc/kernel-build-howto.