ksmbd: break handle caching for share conflicts

ksmbd: break handle caching for share conflicts

smb2.lease.break_twice first opens a file with an RHW lease and then tries
a second open with restrictive sharing.  That open must fail with a sharing
violation, but the existing lease should be broken from RHW to RW because
only handle caching conflicts with the requested sharing.

ksmbd used the normal write-cache break calculation for this path, so RHW
was broken to RH.  The following successful open then did not generate the
expected second break from RW to R.

Pass share-conflict context into the lease break helper and, for lease
breaks caused by sharing, drop only SMB2_LEASE_HANDLE_CACHING from the
current lease state.  Other break paths keep the existing write/truncate
break behavior.

A share-conflict break must also remain a single break.  The triggering
open fails with a sharing violation and is never granted, so there is no
target oplock level to converge on.  The lease break retry loop, however,
keeps breaking while the lease level is still above req_op_level, which
broke RHW all the way down to R in one open (lease_break_info.count became
2 instead of 1).  Skip the again loop for share-conflict breaks so the
sharing open produces exactly one RHW->RW break and the later successful
open produces the separate RW->R break the test expects.

Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>