Don't overflow a buffer on the server's stack at startup

Don't overflow a buffer on the server's stack at startup

The servers like to log the command line it was invoked with.
It does this by concatenating its arguments, separated by spaces,
into a 150-character buffer on the stack of main(). That's just
wrong. Use a dynamically-allocated buffer instead.

Change-Id: Ibe398e5f449eec176f11f301090a1b68ef13e94b
Reviewed-on: http://gerrit.openafs.org/2275
Tested-by: Derrick Brashear <shadow@dementia.org>
Reviewed-by: Andrew Deason <adeason@sinenomine.net>
Reviewed-by: Derrick Brashear <shadow@dementia.org>