Revert "cifs: advertise the right receive buffer size to the server"

This reverts commit c4d3396.

Problems discovered with readdir to Samba due to
not accounting for header size properly with this change

fs/cifs/sess.c

@@ -124,8 +124,7 @@ static __u32 cifs_ssetup_hdr(struct cifs_ses *ses, SESSION_SETUP_ANDX *pSMB)
 	/*	that we use in next few lines                               */
 	/* Note that header is initialized to zero in header_assemble */
 	pSMB->req.AndXCommand = 0xFF;
-	pSMB->req.MaxBufferSize = cpu_to_le16(min_t(u32, CIFSMaxBufSize - 4,
-						USHRT_MAX));
+	pSMB->req.MaxBufferSize = cpu_to_le16(ses->server->maxBuf);
 	pSMB->req.MaxMpxCount = cpu_to_le16(ses->server->maxReq);
 	pSMB->req.VcNumber = get_next_vcnum(ses);