[PATCH] proc: Remove useless BKL in proc_pid_readlink

We already call everything except do_proc_readlink outside of the BKL in
proc_pid_followlink, and there appears to be nothing in do_proc_readlink that
needs any special protection.

So remove this leftover from one of the BKL cleanup efforts.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>