use CLOCKSOURCE_MASK() instead of too large constant

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

arch/ia64/kernel/time.c

@@ -52,7 +52,7 @@ static struct clocksource clocksource_itc = {
         .name           = "itc",
         .rating         = 350,
         .read           = itc_get_cycles,
-        .mask           = 0xffffffffffffffff,
+        .mask           = CLOCKSOURCE_MASK(64),
         .mult           = 0, /*to be caluclated*/
         .shift          = 16,
         .flags          = CLOCK_SOURCE_IS_CONTINUOUS,

drivers/char/hpet.c

@@ -73,7 +73,7 @@ static struct clocksource clocksource_hpet = {
         .name           = "hpet",
         .rating         = 250,
         .read           = read_hpet,
-        .mask           = 0xffffffffffffffff,
+        .mask           = CLOCKSOURCE_MASK(64),
         .mult           = 0, /*to be caluclated*/
         .shift          = 10,
         .flags          = CLOCK_SOURCE_IS_CONTINUOUS,