10132 smatch fixes for MDB
Reviewed by: Andy Fiddaman <andy@omniosce.org>

@@ -21,10 +21,14 @@
 /*
  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
  * Use is subject to license terms.
  */
 
+/*
+ * Copyright (c) 2018, Joyent, Inc.
+ */
+
 #include <sys/elf.h>
 #include <sys/elf_SPARC.h>
 
 #include <libproc.h>
 #include <libctf.h>

@@ -783,11 +787,11 @@
 
         if (optf & (NM_SORT_NAME | NM_SORT_VALUE)) {
                 for (symp = syms; nsyms-- != 0; symp++) {
                         nii.nii_fp = symp->nm_fp;
 
-                        callback(&nii, &symp->nm_sym, symp->nm_name,
+                        (void) callback(&nii, &symp->nm_sym, symp->nm_name,
                             &symp->nm_si, symp->nm_object);
                 }
 
         } else {
                 if (optf & NM_PRVSYM) {