Btrfs: use BTRFS_ERROR_DEV_MISSING_NOT_FOUND when missing device is not found

Use btrfs specific error code BTRFS_ERROR_DEV_MISSING_NOT_FOUND instead
of -ENOENT.  Next this removes the logging when user specifies "missing"
and we don't find it in the kernel device list. Logging are for system
events not for user input errors.
Signed-off-by: NAnand Jain <anand.jain@oracle.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

fs/btrfs/volumes.c

@@ -2041,10 +2041,8 @@ int btrfs_find_device_missing_or_by_path(struct btrfs_root *root,
 			}
 		}
 
-		if (!*device) {
-			btrfs_err(root->fs_info, "no missing device found");
-			return -ENOENT;
-		}
+		if (!*device)
+			return BTRFS_ERROR_DEV_MISSING_NOT_FOUND;
 
 		return 0;
 	} else {