bridge: Adjust min age inc for HZ > 256

min age increment needs to round up its min age tick for all
HZ values to guarantee message age is increasing.
Signed-off-by: NJoakim Tjernlund <Joakim.Tjernlund@transmode.se>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/bridge/br_stp.c

@@ -17,9 +17,9 @@
 #include "br_private_stp.h"
 
 /* since time values in bpdu are in jiffies and then scaled (1/256)
- * before sending, make sure that is at least one.
+ * before sending, make sure that is at least one STP tick.
  */
-#define MESSAGE_AGE_INCR	((HZ < 256) ? 1 : (HZ/256))
+#define MESSAGE_AGE_INCR	((HZ / 256) + 1)
 
 static const char *const br_port_state_names[] = {
 	[BR_STATE_DISABLED] = "disabled",