[Dovecot] io leak when dnotify is enabled but not available

Hi,

When dnotify is enabled, but not in the kernel, there's an io leak:

$ /sbin/dovecot --exec-mail imap

• PREAUTH [CAPABILITY IMAP4rev1 SORT THREAD=REFERENCES MULTIAPPEND UNSELECT LITERAL+ IDLE CHILDREN NAMESPACE LOGIN-REFERRALS] Logged in as johannes a select inbox
• FLAGS (\Answered \Flagged \Deleted \Seen \Draft)
• OK [PERMANENTFLAGS (\Answered \Flagged \Deleted \Seen \Draft \*)] Flags permitted.
• 787 EXISTS
• 0 RECENT
• OK [UIDVALIDITY 1106061449] UIDs valid
• OK [UIDNEXT 790] Predicted next UID a OK [READ-WRITE] Select completed. b IDLE imap(johannes): Error: fcntl(F_NOTIFY) failed: Invalid argument imap(johannes): Error: fcntl(F_NOTIFY) failed: Invalid argument

• idling DONE b OK Idle completed. q logout

• BYE Logging out q OK Logout completed. imap(johannes): Warning: I/O leak: 0x10068ff0 (8)

Attached patch fixes it, I hope the patch is correct :)

johannes