ARM: pm: allow suspend finisher to return error codes

There are SoCs where attempting to enter a low power state is ignored,
and the CPU continues executing instructions with all state preserved.
It is over-complex at that point to disable the MMU just to call the
resume path.

Instead, allow the suspend finisher to return error codes to abort
suspend in this circumstance, where the cpu_suspend internals will then
unwind the saved state on the stack.  Also omit the tlb flush as no
changes to the page tables will have happened.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

arch/arm/mach-s3c64xx/pm.c

@@ -112,7 +112,7 @@ void s3c_pm_save_core(void)
  * this.
  */
 
-static void s3c64xx_cpu_suspend(unsigned long arg)
+static int s3c64xx_cpu_suspend(unsigned long arg)
 {
 	unsigned long tmp;