DelEntry() fix in WildcardMatch module.

This small patch fixes DelEntry routine that is invoked by
CommandDelete() function. Hashtable's Remove function returns
false on failure. The conditional expression that captures this
event is incorrect (if condition in line 306 fails). This patch
uses boolean variables to fix this issue.

Signed-off-by: Muhammad Asim Jamshed <muhammad.jamshed@intel.com>

Author: a-jamshed

core/modules/wildcard_match.cc

@@ -299,19 +299,19 @@ int WildcardMatch::AddTuple(wm_hkey_t *mask) {
   return int(tuples_.size() - 1);
 }
 
-int WildcardMatch::DelEntry(int idx, wm_hkey_t *key) {
+bool WildcardMatch::DelEntry(int idx, wm_hkey_t *key) {
   struct WmTuple &tuple = tuples_[idx];
-  int ret =
+  bool ret =
       tuple.ht.Remove(*key, wm_hash(total_key_size_), wm_eq(total_key_size_));
-  if (ret) {
+  if (ret == false) {
     return ret;
   }
 
   if (tuple.ht.Count() == 0) {
     tuples_.erase(tuples_.begin() + idx);
   }
 
-  return 0;
+  return true;
 }
 
 CommandResponse WildcardMatch::CommandAdd(
@@ -368,9 +368,9 @@ CommandResponse WildcardMatch::CommandDelete(
     return CommandFailure(-idx, "failed to delete a rule");
   }
 
-  int ret = DelEntry(idx, &key);
-  if (ret < 0) {
-    return CommandFailure(-ret, "failed to delete a rule");
+  bool ret = DelEntry(idx, &key);
+  if (ret == false) {
+    return CommandFailure(-EINVAL, "failed to delete a rule");
   }
 
   return CommandSuccess();

core/modules/wildcard_match.h

@@ -170,7 +170,7 @@ class WildcardMatch final : public Module {
 
   int FindTuple(wm_hkey_t *mask);
   int AddTuple(wm_hkey_t *mask);
-  int DelEntry(int idx, wm_hkey_t *key);
+  bool DelEntry(int idx, wm_hkey_t *key);
 
   void Clear();