[SPARC64] arch/sparc64/kernel/unaligned.c: Use time_* macros

The functions time_before, time_before_eq, time_after, and
time_after_eq are more robust for comparing jiffies against other
values.

So following patch implements usage of the time_after() macro, defined
at linux/jiffies.h, which deals with wrapping correctly

Signed-off-by: S.Çağlar Onur <caglar@pardus.org.tr>
Signed-off-by: David S. Miller <davem@davemloft.net>