ACPI: EC: Fix logspam in "GPE storm avoidance" code

[Alan Jenkins <alan-jenkins@tuffmail.co.uk>]

<http://bugzilla.kernel.org/show_bug.cgi?id=11841>
"plenty of line "ACPI: EC: non-query interrupt received,
 switching to interrupt mode" in dmesg"

GPE storm avoidance involves disabling the EC GPE during transactions.
Unfortunately we forget to re-enable EC_FLAGS_GPE_MODE afterwards.

This happens to work because we re-enable it anyway when we detect
the first confirmation interrupt of the next transaction.  However,
this causes lots of bogus "switching to interrupt mode" messages.

Signed-off-by: Alan Jenkins <alan-jenkins@tuffmail.co.uk>

diff --git a/drivers/acpi/ec.c b/drivers/acpi/ec.c
index 7f0d81c..ba47c7c 100644
--- a/drivers/acpi/ec.c
+++ b/drivers/acpi/ec.c
@@ -285,6 +285,7 @@ static int acpi_ec_transaction_unlocked(struct acpi_ec *ec, u8 command,
 		/* check if we received SCI during transaction */
 		ec_check_sci(ec, acpi_ec_read_status(ec));
 		/* it is safe to enable GPE outside of transaction */
+		set_bit(EC_FLAGS_GPE_MODE, &ec->flags);
 		acpi_enable_gpe(NULL, ec->gpe, ACPI_NOT_ISR);
 	} else if (test_bit(EC_FLAGS_GPE_MODE, &ec->flags) &&
 		   t.irq_count > ACPI_EC_STORM_THRESHOLD) {