drivers/bch: ioctl() - BIOC_FLUSH: Add calling ioctl() of block driver

Passing `BIOC_FLUSH` to block driver to ensure that changes transfers ("flushes") to the block device

Signed-off-by: wangjianyu3 <wangjianyu3@xiaomi.com>

drivers/bch/bchdev_driver.c

@@ -420,14 +420,6 @@ static int bch_ioctl(FAR struct file *filep, int cmd, unsigned long arg)
         }
         break;
 
-      case BIOC_FLUSH:
-        {
-          /* Flush any dirty pages remaining in the cache */
-
-          ret = bchlib_flushsector(bch, false);
-        }
-        break;
-
 #ifdef CONFIG_BCH_ENCRYPTION
       /* This is a request to set the encryption key? */
 
@@ -439,9 +431,20 @@ static int bch_ioctl(FAR struct file *filep, int cmd, unsigned long arg)
         break;
 #endif
 
-      /* Otherwise, pass the IOCTL command on to the contained block
-       * driver.
-       */
+      case BIOC_FLUSH:
+        {
+          /* Flush any dirty pages remaining in the cache */
+
+          ret = bchlib_flushsector(bch, false);
+          if (ret < 0)
+            {
+              break;
+            }
+
+          /* Go through */
+        }
+
+      /* Pass the IOCTL command on to the contained block driver. */
 
       default:
         {