10076 make usr/src/test smatch clean

@@ -66,11 +66,11 @@
         }
 
         if (rc == 0) {
                 done = 1;
                 ucp.uc_mcontext.gregs[seg] = selector;
-                setcontext(&ucp);
+                (void) setcontext(&ucp);
         }
         abort();
 }
 
 static void