example/bdev/hellow_word: Drop .ini config in favor of json

Change-Id: I019a58860cb020e6a4071efb898b513a11c44554
Signed-off-by: wanghailiangx <hailiangx.e.wang@intel.com>
Reviewed-on: https://review.spdk.io/gerrit/c/spdk/spdk/+/4846
Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>
Reviewed-by: Tomasz Zawadzki <tomasz.zawadzki@intel.com>
Reviewed-by: Aleksey Marchuk <alexeymar@mellanox.com>

examples/bdev/hello_world/bdev.conf

@@ -1,3 +0,0 @@
-[Malloc]
-  NumberOfLuns 1
-  LunSizeInMB  32

examples/bdev/hello_world/bdev.json

@@ -0,0 +1,17 @@
+{
+  "subsystems": [
+    {
+      "subsystem": "bdev",
+      "config": [
+        {
+          "method": "bdev_malloc_create",
+          "params": {
+            "name": "Malloc0",
+            "num_blocks": 32768,
+            "block_size": 512
+          }
+        }
+      ]
+    }
+  ]
+}