Correct a couple expiry time checks from DoTime()

modules/commands/bs_set.cpp

@@ -114,7 +114,7 @@ class CommandBSSetBanExpire : public Command
 		}
 
 		time_t t = Anope::DoTime(arg);
-		if (t == -1)
+		if (t < 0)
 		{
 			source.Reply(BAD_EXPIRY_TIME);
 			return;

modules/commands/cs_ban.cpp

@@ -70,7 +70,7 @@ class CommandCSBan : public Command
 		if (params[1][0] == '+')
 		{
 			ban_time = Anope::DoTime(params[1]);
-			if (ban_time == -1)
+			if (ban_time < 0)
 			{
 				source.Reply(BAD_EXPIRY_TIME);
 				return;

modules/commands/cs_suspend.cpp

@@ -75,7 +75,7 @@ class CommandCSSuspend : public Command
 		else
 		{
 			expiry_secs = Anope::DoTime(expiry);
-			if (expiry_secs == -1)
+			if (expiry_secs < 0)
 			{
 				source.Reply(BAD_EXPIRY_TIME);
 				return;

modules/commands/ns_suspend.cpp

@@ -81,7 +81,7 @@ class CommandNSSuspend : public Command
 		else
 		{
 			expiry_secs = Anope::DoTime(expiry);
-			if (expiry_secs == -1)
+			if (expiry_secs < 0)
 			{
 				source.Reply(BAD_EXPIRY_TIME);
 				return;

modules/commands/os_forbid.cpp

@@ -187,7 +187,7 @@ class CommandOSForbid : public Command
 			if (!expiry.empty())
 			{
 				expiryt = Anope::DoTime(expiry);
-				if (expiryt == -1)
+				if (expiryt < 0)
 				{
 					source.Reply(BAD_EXPIRY_TIME);
 					return;