ext4: make orphan functions be no-op in no-journal mode

commit c9b92530a723ac5ef8e352885a1862b18f31b2f5 upstream.

Instead of checking whether the handle is valid, we check if journal
is enabled. This avoids taking the s_orphan_lock mutex in all cases
when there is no journal in use, including the error paths where
ext4_orphan_del() is called with a handle set to NULL.

Signed-off-by: Anatol Pomozov <anatol.pomozov@gmail.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
[bwh: Adjust context to apply after commit 0e9a9a1ad619
 ('ext4: avoid hang when mounting non-journal filesystems with orphan list')
 and commit e2bfb088fac0
 ('ext4: don't orphan or truncate the boot loader inode')]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>