[4045] Fixed some cppcheck reports (first round)

src/lib/dhcpsrv/memfile_lease_mgr.cc

@@ -567,7 +567,7 @@ Memfile_LeaseMgr::updateLease4(const Lease4Ptr& lease) {
 
     // Lease must exist if it is to be updated.
     Lease4StorageAddressIndex::const_iterator lease_it = index.find(lease->addr_);
-    if (lease_it == storage4_.end()) {
+    if (lease_it == index.end()) {
         isc_throw(NoSuchLease, "failed to update the lease with address "
                   << lease->addr_ << " - no such lease");
     }

src/lib/hooks/tests/hooks_manager_unittest.cc

@@ -101,10 +101,14 @@ public:
 
 private:
     /// To avoid unused variable errors
-    void dummy() {
-        std::string n = MARKER_FILE;
-        n = LOAD_CALLOUT_LIBRARY;
-        n = LOAD_ERROR_CALLOUT_LIBRARY;
+    std::string dummy(int i) {
+        if (i == 0) {
+            return (MARKER_FILE);
+        } else if (i > 0) {
+            return (LOAD_CALLOUT_LIBRARY);
+        } else {
+            return (LOAD_ERROR_CALLOUT_LIBRARY);
+        }
     }
 };
 

src/lib/hooks/tests/library_manager_collection_unittest.cc

@@ -39,10 +39,14 @@ class LibraryManagerCollectionTest : public ::testing::Test,
                                      public HooksCommonTestClass {
 private:
     /// To avoid unused variable errors
-    void dummy() {
-        std::string n = MARKER_FILE;
-        n = LOAD_CALLOUT_LIBRARY;
-        n = LOAD_ERROR_CALLOUT_LIBRARY;
+    std::string dummy(int i) {
+        if (i == 0) {
+            return (MARKER_FILE);
+        } else if (i > 0) {
+            return (LOAD_CALLOUT_LIBRARY);
+        } else {
+            return (LOAD_ERROR_CALLOUT_LIBRARY);
+        }
     }
 };