ctdb-recovery: Negate the status when checking the recovery lock

ctdb-recovery: Negate the status when checking the recovery lock

Have 0 indicate that the lock was taken.  This allows non-zero values
to be used to indicate why the lock could not be taken.  EACCES means
lock contention.

For now use just EACCES to cover all failures, since
ctdb_recovery_lock() returns a bool and details of other errors will
be lost.  ctdb_recovery_lock() will undergo some big changes, so don't
try to fix this now.

Signed-off-by: Martin Schwenke <martin@meltin.net>
Reviewed-by: Amitay Isaacs <amitay@gmail.com>