net/smc: Eliminate struct smc_ism_position

This struct is used in a single place only, and its usage generates
inefficient code. Time to clean up!

Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Reviewed-and-tested-by: Stefan Raspl <raspl@linux.ibm.com>
Signed-off-by: Wenjia Zhang &lt; <wenjia@linux.ibm.com>
Reviewed-by: Tony Lu <tonylu@linux.alibaba.com>
Signed-off-by: David S. Miller <davem@davemloft.net>