x86/MCE: Remove min interval polling limitation

commit b3b7c47 ("x86/MCE: Serialize sysfs changes") introduced a min
interval limitation when setting the check interval for polled MCEs.
However, the logic is that 0 disables polling for corrected MCEs, see
Documentation/x86/x86_64/machinecheck. The limitation prevents disabling.

Remove this limitation and allow the value 0 to disable polling again.

Fixes: b3b7c47 ("x86/MCE: Serialize sysfs changes")
Signed-off-by: Dewet Thibaut <thibaut.dewet@nokia.com>
Signed-off-by: Alexander Sverdlin <alexander.sverdlin@nokia.com>
[ Massage commit message. ]
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: linux-edac <linux-edac@vger.kernel.org>
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/20180716084927.24869-1-alexander.sverdlin@nokia.com

arch/x86/kernel/cpu/mcheck/mce.c

@@ -2165,9 +2165,6 @@ static ssize_t store_int_with_restart(struct device *s,
 	if (check_interval == old_check_interval)
 		return ret;
 
-	if (check_interval < 1)
-		check_interval = 1;
-
 	mutex_lock(&mce_sysfs_mutex);
 	mce_restart();
 	mutex_unlock(&mce_sysfs_mutex);