raw: Add missing annotations to raw_seq_start() and raw_seq_stop()

raw: Add missing annotations to raw_seq_start() and raw_seq_stop()

Sparse reports warnings at raw_seq_start() and raw_seq_stop()

warning: context imbalance in raw_seq_start() - wrong count at exit
warning: context imbalance in raw_seq_stop() - unexpected unlock

The root cause is the missing annotations at raw_seq_start()
	and raw_seq_stop()
Add the missing __acquires(&h->lock) annotation
Add the missing __releases(&h->lock) annotation

Signed-off-by: Jules Irenge <jbi.octave@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>