10687 Service routine cast changes need smatch fixes

@@ -22,10 +22,14 @@
  * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
  * Use is subject to license terms.
  */
 
 /*
+ * Copyright 2019, Joyent, Inc.
+ */
+
+/*
  * Softmac data-path switching:
  *
  * - Fast-path model
  *
  * When the softmac fast-path is used, a dedicated lower-stream

@@ -762,11 +766,11 @@
         /*
          * No need to hold lock to check su_mode, since su_mode updating only
          * operation is is serialized by softmac_wput_nondata_task().
          */
         if (sup->su_mode != SOFTMAC_FASTPATH) {
-                dld_wput(sup->su_wq, mp);
+                (void) dld_wput(sup->su_wq, mp);
                 return;
         }
 
         /*
          * Fastpath non-data message processing. Most of non-data messages

@@ -984,11 +988,11 @@
          * No lock is required to access the su_mode field since the data
          * traffic is quiesce by IP when the data-path mode is in the
          * process of switching.
          */
         if (sup->su_mode != SOFTMAC_FASTPATH)
-                dld_wput(sup->su_wq, mp);
+                (void) dld_wput(sup->su_wq, mp);
         else
                 (void) softmac_fastpath_wput_data(sup, mp, NULL, 0);
 }
 
 /*ARGSUSED*/