nvram: Drop the bkl from non-generic nvram_llseek()

Drop the bkl from nvram_llseek() as it obviously protects nothing.
The file offset is safe in essence.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <1255116426-7270-1-git-send-email-fweisbec@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>