hpsa: remove bad unlikely annotation from device list updating code

Signed-off-by: Stephen M. Cameron <scameron@beardog.cce.hp.com>
Reviewed-by: Justin Lindley <justin.lindley@hp.com>
Reviewed-by: Mike Miller <michael.miller@canonical.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>