powerpc/tau: Remove duplicated set_thresholds() call

The commentary at the call site seems to disagree with the code. The
conditional prevents calling set_thresholds() via the exception handler,
which appears to crash. Perhaps that's because it immediately triggers
another TAU exception. Anyway, calling set_thresholds() from TAUupdate()
is redundant because tau_timeout() does so.

Fixes: 1da177e4 ("Linux-2.6.12-rc2")
Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Tested-by: Stan Johnson <userm57@yahoo.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/d7c7ee33232cf72a6a6bbb6ef05838b2e2b113c0.1599260540.git.fthain@telegraphics.com.au

arch/powerpc/kernel/tau_6xx.c

@@ -110,11 +110,6 @@ static void TAUupdate(int cpu)
 #ifdef DEBUG
 	printk("grew = %d\n", tau[cpu].grew);
 #endif
-
-#ifndef CONFIG_TAU_INT /* tau_timeout will do this if not using interrupts */
-	set_thresholds(cpu);
-#endif
-
 }
 
 #ifdef CONFIG_TAU_INT