refperf: Work around 64-bit division

A 64-bit division was introduced in refperf, breaking compilation
on all 32-bit architectures:

kernel/rcu/refperf.o: in function `main_func':
refperf.c:(.text+0x57c): undefined reference to `__aeabi_uldivmod'

Fix this by using div_u64 to mark the expensive operation.

[ paulmck: Update primitive and format per Nathan Chancellor. ]
Fixes: bd5b16d6c88d ("refperf: Allow decimal nanoseconds")
Reported-by: kbuild test robot <[email protected]>
Reported-by: Valdis Klētnieks <[email protected]>
Acked-by: Randy Dunlap <[email protected]> # build-tested
Signed-off-by: Arnd Bergmann <[email protected]>
Signed-off-by: Paul E. McKenney <[email protected]>

0 files changed, 0 insertions, 0 deletions