[SCSI] zfcp: Add __init declaration to zfcp_cache_hw_align

The function zfcp_cache_hw_align is only called from zfcp_module_init,
so it should be declared with __init as well.

Reviewed-by: Steffen Maier <maier@linux.vnet.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>