From: Manfred Spraul <manfred@colorfullife.com>

cleanup of sysv ipc as a preparation for posix message queues:

- replace !CONFIG_SYSVIPC wrappers for copy_semundo and exit_sem with
  static inline wrappers.  Now the whole ipc/util.c file is only used if
  CONFIG_SYSVIPC is set, use makefile magic instead of #ifdef.

- remove the prototypes for copy_semundo and exit_sem from kernel/fork.c

- they belong into a header file.

- create a new msgutil.c with the helper functions for message queues.

- cleanup the helper functions: run Lindent, add __user tags.