smb3: add dynamic tracepoint for timeout waiting for credits

To help debug credit starvation problems where we timeout
waiting for server to grant the client credits.

Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>

fs/cifs/trace.h

@@ -713,6 +713,7 @@ DEFINE_EVENT(smb3_credit_class, smb3_##name,  \
 	TP_ARGS(currmid, hostname, credits))
 
 DEFINE_SMB3_CREDIT_EVENT(reconnect_with_invalid_credits);
+DEFINE_SMB3_CREDIT_EVENT(credit_timeout);
 
 #endif /* _CIFS_TRACE_H */