[NET]: Remove lockdep_set_class() call from skb_queue_head_init().

The skb_queue_head_init() function is used both in drivers for private use
and in the core networking code.  The usage models are vastly set of
functions that is only softirq safe; while the driver usage tends to be
more limited to a few hardirq safe accessor functions.  Rather than
annotating all 133+ driver usages, for now just split this lock into a per
queue class.  This change is obviously safe and probably should make
2.6.18.

Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: David S. Miller <davem@davemloft.net>