net/smc: Print function name in smcr_link_down tracepoint

This makes the output of smcr_link_down tracepoint easier to use and
understand without additional translating function's pointer address.

It prints the function name with offset:

  <idle>-0       [000] ..s.    69.087164: smcr_link_down: lnk=00000000dab41cdc lgr=000000007d5d8e24 state=0 rc=1 dev=mlx5_0 location=smc_wr_tx_tasklet_fn+0x5ef/0x6f0 [smc]

Link: https://lore.kernel.org/netdev/11f17a34-fd35-f2ec-3f20-dd0c34e55fde@linux.ibm.com/Signed-off-by: Tony Lu <tonylu@linux.alibaba.com>
Reviewed-by: Wen Gu <guwen@linux.alibaba.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/smc/smc_tracepoint.h

@@ -99,7 +99,7 @@ TRACE_EVENT(smcr_link_down,
 			   __entry->location = location;
 	    ),
 
-	    TP_printk("lnk=%p lgr=%p state=%d dev=%s location=%p",
+	    TP_printk("lnk=%p lgr=%p state=%d dev=%s location=%pS",
 		      __entry->lnk, __entry->lgr,
 		      __entry->state, __get_str(name),
 		      __entry->location)