powerpc: Fix workaround for spurious MCE on POWER9

In the recent commit d8bd9f3f09 ("powerpc: Handle MCE on POWER9 with
only DSISR bit 30 set") I screwed up the bit number. It should be bit
25 (IBM bit 38).

Fixes: d8bd9f3f09 ("powerpc: Handle MCE on POWER9 with only DSISR bit 30 set")
Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

arch/powerpc/kernel/mce_power.c

@@ -626,7 +626,7 @@ long __machine_check_early_realmode_p9(struct pt_regs *regs)
 {
 	/*
 	 * On POWER9 DD2.1 and below, it's possible to get a machine check
-	 * caused by a paste instruction where only DSISR bit 30 is set. This
+	 * caused by a paste instruction where only DSISR bit 25 is set. This
 	 * will result in the MCE handler seeing an unknown event and the kernel
 	 * crashing. An MCE that occurs like this is spurious, so we don't need
 	 * to do anything in terms of servicing it. If there is something that
@@ -634,7 +634,7 @@ long __machine_check_early_realmode_p9(struct pt_regs *regs)
 	 * correct DSISR so that it can be serviced properly. So detect this
 	 * case and mark it as handled.
 	 */
-	if (SRR1_MC_LOADSTORE(regs->msr) && regs->dsisr == 0x40000000)
+	if (SRR1_MC_LOADSTORE(regs->msr) && regs->dsisr == 0x02000000)
 		return 1;
 
 	return mce_handle_error(regs, mce_p9_derror_table, mce_p9_ierror_table);