iproute: rename 'get_jiffies' since it uses msecs

The get_jiffies() function retrieves rtt-type values in units of
milliseconds. This patch updates the function name accordingly,
following the pattern given by dst_metric() <=> dst_metric_rtt().
diff --git a/ip/iproute.c b/ip/iproute.c
index d48e743..06d2507 100644
--- a/ip/iproute.c
+++ b/ip/iproute.c
@@ -835,7 +835,7 @@
 				mxlock |= (1<<RTAX_RTT);
 				NEXT_ARG();
 			}
-			if (get_jiffies(&rtt, *argv, &raw))
+			if (get_time_rtt(&rtt, *argv, &raw))
 				invarg("\"rtt\" value is invalid\n", *argv);
 			rta_addattr32(mxrta, sizeof(mxbuf), RTAX_RTT, 
 				(raw) ? rtt : rtt * 8);
@@ -843,7 +843,7 @@
 			unsigned rto_min;
 			NEXT_ARG();
 			mxlock |= (1<<RTAX_RTO_MIN);
-			if (get_jiffies(&rto_min, *argv, &raw))
+			if (get_time_rtt(&rto_min, *argv, &raw))
 				invarg("\"rto_min\" value is invalid\n",
 				       *argv);
 			rta_addattr32(mxrta, sizeof(mxbuf), RTAX_RTO_MIN,
@@ -895,7 +895,7 @@
 				mxlock |= (1<<RTAX_RTTVAR);
 				NEXT_ARG();
 			}
-			if (get_jiffies(&win, *argv, &raw))
+			if (get_time_rtt(&win, *argv, &raw))
 				invarg("\"rttvar\" value is invalid\n", *argv);
 			rta_addattr32(mxrta, sizeof(mxbuf), RTAX_RTTVAR,
 				(raw) ? win : win * 4);