smb: client: disable directory caching when dir_cache_timeout is zero

Setting dir_cache_timeout to zero should disable the caching of
directory contents. Currently, even when dir_cache_timeout is zero,
some caching related functions are still invoked, which is unintended
behavior.

Fix the issue by setting tcon->nohandlecache to true when
dir_cache_timeout is zero, ensuring that directory handle caching
is properly disabled.

Fixes: 238b351 ("smb3: allow controlling length of time directory entries are cached with dir leases")
Reviewed-by: Paulo Alcantara (Red Hat) <pc@manguebit.com>
Reviewed-by: Enzo Matsumiya <ematsumiya@suse.de>
Signed-off-by: Henrique Carvalho <henrique.carvalho@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

fs/smb/client/connect.c

@@ -2571,7 +2571,7 @@ cifs_get_tcon(struct cifs_ses *ses, struct smb3_fs_context *ctx)
 
 	if (ses->server->dialect >= SMB20_PROT_ID &&
 	    (ses->server->capabilities & SMB2_GLOBAL_CAP_DIRECTORY_LEASING))
-		nohandlecache = ctx->nohandlecache;
+		nohandlecache = ctx->nohandlecache || !dir_cache_timeout;
 	else
 		nohandlecache = true;
 	tcon = tcon_info_alloc(!nohandlecache, netfs_trace_tcon_ref_new);