RDMA/core/iwpm_util: Fix some param description misspellings

Fixes the following W=1 kernel build warning(s):

 drivers/infiniband/core/iwpm_util.c:138: warning: Function parameter or member 'local_sockaddr' not described in 'iwpm_create_mapinfo'
 drivers/infiniband/core/iwpm_util.c:138: warning: Function parameter or member 'mapped_sockaddr' not described in 'iwpm_create_mapinfo'
 drivers/infiniband/core/iwpm_util.c:138: warning: Excess function parameter 'local_addr' description in 'iwpm_create_mapinfo'
 drivers/infiniband/core/iwpm_util.c:138: warning: Excess function parameter 'mapped_addr' description in 'iwpm_create_mapinfo'
 drivers/infiniband/core/iwpm_util.c:185: warning: Function parameter or member 'local_sockaddr' not described in 'iwpm_remove_mapinfo'
 drivers/infiniband/core/iwpm_util.c:185: warning: Excess function parameter 'local_addr' description in 'iwpm_remove_mapinfo'

Link: https://lore.kernel.org/r/20210118223929.512175-20-lee.jones@linaro.org
Cc: Doug Ledford <dledford@redhat.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: linux-rdma@vger.kernel.org
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>