Linux: specify void argument for afs_try_to_freeze inlines

Linux: specify void argument for afs_try_to_freeze inlines

The new freeze inlines take no arguments, but need to be declared
as taking (void) to prevent warnings that it is not a proper prototype.

Change-Id: Ife675e69f566fabaee4bc41f2cc4fa9a20e816db
Reviewed-on: http://gerrit.openafs.org/1870
Reviewed-by: Simon Wilkinson <sxw@inf.ed.ac.uk>
Reviewed-by: Derrick Brashear <shadow@dementia.org>
Tested-by: Derrick Brashear <shadow@dementia.org>