rxrpc: Fix loss of PING RESPONSE ACK production due to PING ACKs

Separate the output of PING ACKs from the output of other sorts of ACK so
that if we receive a PING ACK and schedule transmission of a PING RESPONSE
ACK, the response doesn't get cancelled by a PING ACK we happen to be
scheduling transmission of at the same time.

If a PING RESPONSE gets lost, the other side might just sit there waiting
for it and refuse to proceed otherwise.

Signed-off-by: David Howells <dhowells@redhat.com>
diff --git a/net/rxrpc/misc.c b/net/rxrpc/misc.c
index 804a88e..1cdcba5 100644
--- a/net/rxrpc/misc.c
+++ b/net/rxrpc/misc.c
@@ -93,7 +93,6 @@
 	[RXRPC_ACK_EXCEEDS_WINDOW]	= 6,
 	[RXRPC_ACK_NOSPACE]		= 7,
 	[RXRPC_ACK_PING_RESPONSE]	= 8,
-	[RXRPC_ACK_PING]		= 9,
 };
 
 const char rxrpc_ack_names[RXRPC_ACK__INVALID + 1][4] = {
@@ -197,6 +196,7 @@
 	[rxrpc_timer_expired]			= "*EXPR*",
 	[rxrpc_timer_init_for_reply]		= "IniRpl",
 	[rxrpc_timer_set_for_ack]		= "SetAck",
+	[rxrpc_timer_set_for_ping]		= "SetPng",
 	[rxrpc_timer_set_for_send]		= "SetTx ",
 	[rxrpc_timer_set_for_resend]		= "SetRTx",
 };