ia64: Trivial stack-size correction in mca.c. Patch by Keith Owens.

arch/ia64/kernel/mca.c

@@ -71,7 +71,7 @@ u64				ia64_mca_proc_state_dump[512];
 u64				ia64_mca_stack[1024] __attribute__((aligned(16)));
 u64				ia64_mca_stackframe[32];
 u64				ia64_mca_bspstore[1024];
-u64				ia64_init_stack[KERNEL_STACK_SIZE] __attribute__((aligned(16)));
+u64				ia64_init_stack[KERNEL_STACK_SIZE/8] __attribute__((aligned(16)));
 u64				ia64_mca_sal_data_area[1356];
 u64				ia64_tlb_functional;
 u64				ia64_os_mca_recovery_successful;