NSM: Use modern style for sm_name field in nsm_handle

Clean up: I'm about to add another "char *" field to the nsm_handle
structure.  The sm_name field uses an older style of declaring a
"char *" field.  If I match that style for the new field, checkpatch.pl
will complain.

So, fix the sm_name field to use the new style.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>