btrfs: remove no longer needed full sync flag check at inode_logged()

Now that we are checking if the inode's logged_trans is 0 to detect the
possibility of the inode having been evicted and reloaded, the test for
the full sync flag (BTRFS_INODE_NEEDS_FULL_SYNC) is no longer needed at
tree-log.c:inode_logged(). Its purpose was to detect the possibility
of a previous eviction as well, since when an inode is loaded the full
sync flag is always set on it (and only cleared after the inode is
logged).

So just remove the check and update the comment. The check for the inode's
logged_trans being 0 was added recently by the patch with the subject
"btrfs: eliminate some false positives when checking if inode was logged".
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

fs/btrfs/tree-log.c

@@ -3435,16 +3435,14 @@ static bool inode_logged(struct btrfs_trans_handle *trans,
 	/*
 	 * The inode's logged_trans is always 0 when we load it (because it is
 	 * not persisted in the inode item or elsewhere). So if it is 0, the
-	 * inode was last modified in the current transaction and has the
-	 * full_sync flag set, then the inode may have been logged before in
-	 * the current transaction, then evicted and loaded again in the current
-	 * transaction - or may have never been logged in the current transaction,
-	 * but since we can not be sure, we have to assume it was, otherwise our
-	 * callers can leave an inconsistent log.
+	 * inode was last modified in the current transaction then the inode may
+	 * have been logged before in the current transaction, then evicted and
+	 * loaded again in the current transaction - or may have never been logged
+	 * in the current transaction, but since we can not be sure, we have to
+	 * assume it was, otherwise our callers can leave an inconsistent log.
 	 */
 	if (inode->logged_trans == 0 &&
 	    inode->last_trans == trans->transid &&
-	    test_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &inode->runtime_flags) &&
 	    !test_bit(BTRFS_FS_LOG_RECOVERING, &trans->fs_info->flags))
 		return true;