timekeeping: Fixup typo in update_vsyscall_old definition

timekeeping: Fixup typo in update_vsyscall_old definition

In commit 4a0e637738f0 ("clocksource: Get rid of cycle_last"),
currently in the -tip tree, there was a small typo where cycles_t
was used intstead of cycle_t. This broke ppc64 builds.

Fix this by using the proper cycle_t type for this usage, in
both the definition and the ia64 implementation.

Now, having both cycle_t and cycles_t types seems like a very
bad idea just asking for these sorts of issues. But that
will be a cleanup for another day.

Reported-by: Stephen Rothwell <[email protected]>
Signed-off-by: John Stultz <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: "H. Peter Anvin" <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Thomas Gleixner <[email protected]>