cppcheck: (error) Null pointer dereference: who_perm

As indicated by the VERIFY the local who_perm variable can never
be NULL in parse_fs_perm().  Due to the existence of the is_set
conditional, which is always true, cppcheck 1.88 was reporting
a possible NULL reference.  Resolve the issue by removing the
extraneous is_set variable.

Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes openzfs#9732

cmd/zfs/zfs_main.c

@@ -4896,7 +4896,6 @@ parse_fs_perm(fs_perm_t *fsperm, nvlist_t *nvl)
 		zfs_deleg_who_type_t perm_type = name[0];
 		char perm_locality = name[1];
 		const char *perm_name = name + 3;
-		boolean_t is_set = B_TRUE;
 		who_perm_t *who_perm = NULL;
 
 		assert('$' == name[2]);
@@ -4926,57 +4925,56 @@ parse_fs_perm(fs_perm_t *fsperm, nvlist_t *nvl)
 			assert(!"unhandled zfs_deleg_who_type_t");
 		}
 
-		if (is_set) {
-			who_perm_node_t *found_node = NULL;
-			who_perm_node_t *node = safe_malloc(
-			    sizeof (who_perm_node_t));
-			who_perm = &node->who_perm;
-			uu_avl_index_t idx = 0;
-
-			uu_avl_node_init(node, &node->who_avl_node, avl_pool);
-			who_perm_init(who_perm, fsperm, perm_type, perm_name);
-
-			if ((found_node = uu_avl_find(avl, node, NULL, &idx))
-			    == NULL) {
-				if (avl == fsperm->fsp_uge_avl) {
-					uid_t rid = 0;
-					struct passwd *p = NULL;
-					struct group *g = NULL;
-					const char *nice_name = NULL;
-
-					switch (perm_type) {
-					case ZFS_DELEG_USER_SETS:
-					case ZFS_DELEG_USER:
-						rid = atoi(perm_name);
-						p = getpwuid(rid);
-						if (p)
-							nice_name = p->pw_name;
-						break;
-					case ZFS_DELEG_GROUP_SETS:
-					case ZFS_DELEG_GROUP:
-						rid = atoi(perm_name);
-						g = getgrgid(rid);
-						if (g)
-							nice_name = g->gr_name;
-						break;
+		who_perm_node_t *found_node = NULL;
+		who_perm_node_t *node = safe_malloc(
+		    sizeof (who_perm_node_t));
+		who_perm = &node->who_perm;
+		uu_avl_index_t idx = 0;
 
-					default:
-						break;
-					}
+		uu_avl_node_init(node, &node->who_avl_node, avl_pool);
+		who_perm_init(who_perm, fsperm, perm_type, perm_name);
+
+		if ((found_node = uu_avl_find(avl, node, NULL, &idx))
+		    == NULL) {
+			if (avl == fsperm->fsp_uge_avl) {
+				uid_t rid = 0;
+				struct passwd *p = NULL;
+				struct group *g = NULL;
+				const char *nice_name = NULL;
+
+				switch (perm_type) {
+				case ZFS_DELEG_USER_SETS:
+				case ZFS_DELEG_USER:
+					rid = atoi(perm_name);
+					p = getpwuid(rid);
+					if (p)
+						nice_name = p->pw_name;
+					break;
+				case ZFS_DELEG_GROUP_SETS:
+				case ZFS_DELEG_GROUP:
+					rid = atoi(perm_name);
+					g = getgrgid(rid);
+					if (g)
+						nice_name = g->gr_name;
+					break;
 
-					if (nice_name != NULL)
-						(void) strlcpy(
-						    node->who_perm.who_ug_name,
-						    nice_name, 256);
+				default:
+					break;
 				}
 
-				uu_avl_insert(avl, node, idx);
-			} else {
-				node = found_node;
-				who_perm = &node->who_perm;
+				if (nice_name != NULL)
+					(void) strlcpy(
+					    node->who_perm.who_ug_name,
+					    nice_name, 256);
 			}
+
+			uu_avl_insert(avl, node, idx);
+		} else {
+			node = found_node;
+			who_perm = &node->who_perm;
 		}
-		VERIFY3P(who_perm, !=, NULL);
+
+		assert(who_perm != NULL);
 		(void) parse_who_perm(who_perm, nvl2, perm_locality);
 	}