cifs: fix confusing unneeded warning message on smb2.1 and earlier

BugLink: https://bugs.launchpad.net/bugs/2036450

When mounting with SMB2.1 or earlier, even with nomultichannel, we
log the confusing warning message:
  "CIFS: VFS: multichannel is not supported on this protocol version, use 3.0 or above"

Fix this so that we don't log this unless they really are trying
to mount with multichannel.

BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=215608
Reported-by: Kim Scarborough <kim@scarborough.kim>
Cc: stable@vger.kernel.org # 5.11+
Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>
(cherry picked from commit 53923e0)
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>

fs/cifs/sess.c

@@ -127,11 +127,6 @@ int cifs_try_adding_channels(struct cifs_sb_info *cifs_sb, struct cifs_ses *ses)
 	struct cifs_server_iface *ifaces = NULL;
 	size_t iface_count;
 
-	if (ses->server->dialect < SMB30_PROT_ID) {
-		cifs_dbg(VFS, "multichannel is not supported on this protocol version, use 3.0 or above\n");
-		return 0;
-	}
-
 	spin_lock(&ses->chan_lock);
 
 	new_chan_count = old_chan_count = ses->chan_count;
@@ -145,6 +140,12 @@ int cifs_try_adding_channels(struct cifs_sb_info *cifs_sb, struct cifs_ses *ses)
 		return 0;
 	}
 
+	if (ses->server->dialect < SMB30_PROT_ID) {
+		spin_unlock(&ses->chan_lock);
+		cifs_dbg(VFS, "multichannel is not supported on this protocol version, use 3.0 or above\n");
+		return 0;
+	}
+
 	if (!(ses->server->capabilities & SMB2_GLOBAL_CAP_MULTI_CHANNEL)) {
 		ses->chan_max = 1;
 		spin_unlock(&ses->chan_lock);