net: track success and failure of TCP PMTU probing

Track success and failure of TCP PMTU probing.

Signed-off-by: Rick Jones <rick.jones2@hp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/uapi/linux/snmp.h b/include/uapi/linux/snmp.h
index eee8968..25a9ad8 100644
--- a/include/uapi/linux/snmp.h
+++ b/include/uapi/linux/snmp.h
@@ -278,6 +278,8 @@
 	LINUX_MIB_TCPACKSKIPPEDCHALLENGE,	/* TCPACKSkippedChallenge */
 	LINUX_MIB_TCPWINPROBE,			/* TCPWinProbe */
 	LINUX_MIB_TCPKEEPALIVE,			/* TCPKeepAlive */
+	LINUX_MIB_TCPMTUPFAIL,			/* TCPMTUPFail */
+	LINUX_MIB_TCPMTUPSUCCESS,		/* TCPMTUPSuccess */
 	__LINUX_MIB_MAX
 };