bugfix (nvs): Fixed issues found by Coverity

*  Fixed potential memory leak
*  Fixed wrong strncpy usage
*  Fixed potential out of bounds access

components/nvs_flash/include/nvs.h

@@ -1,16 +1,8 @@
-// Copyright 2015-2016 Espressif Systems (Shanghai) PTE LTD
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
+/*
+ * SPDX-FileCopyrightText: 2015-2022 Espressif Systems (Shanghai) CO LTD
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
 #ifndef ESP_NVS_H
 #define ESP_NVS_H
 
@@ -65,6 +57,7 @@ typedef nvs_handle_t nvs_handle IDF_DEPRECATED("Replace with nvs_handle_t");
 #define NVS_DEFAULT_PART_NAME               "nvs"   /*!< Default partition name of the NVS partition in the partition table */
 
 #define NVS_PART_NAME_MAX_SIZE              16   /*!< maximum length of partition name (excluding null terminator) */
+#define NVS_KEY_NAME_MAX_SIZE               16   /*!< Maximal length of NVS key name (including null terminator) */
 
 /**
  * @brief Mode of opening the non-volatile storage
@@ -103,7 +96,7 @@ typedef enum {
  */
 typedef struct {
     char namespace_name[16];    /*!< Namespace to which key-value belong */
-    char key[16];               /*!< Key of stored key-value pair */
+    char key[NVS_KEY_NAME_MAX_SIZE];               /*!< Key of stored key-value pair */
     nvs_type_t type;            /*!< Type of stored key-value pair */
 } nvs_entry_info_t;