[monitoring-plugins] Fix number of tests

[RincewindsHat]

 Module: monitoring-plugins
 Branch: check_icmp_buffer_offerflow
 Commit: b3b1dd4d12e253f27d5c3bcccdc1f2e8d172cd6c
 Author: RincewindsHat <12514511+RincewindsHat at users.noreply.github.com>
   Date: Tue Jan 25 00:00:11 2022 +0100
    URL: https://www.monitoring-plugins.org/repositories/monitoring-plugins/commit/?id=b3b1dd4

Fix number of tests

---

 plugins-root/t/check_icmp.t | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/plugins-root/t/check_icmp.t b/plugins-root/t/check_icmp.t
index 2fe0513..de53697 100644
--- a/plugins-root/t/check_icmp.t
+++ b/plugins-root/t/check_icmp.t
@@ -12,7 +12,7 @@ my $allow_sudo = getTestParameter( "NP_ALLOW_SUDO",
 	"no" );
 
 if ($allow_sudo eq "yes" or $> == 0) {
-	plan tests => 20;
+	plan tests => 18;
 } else {
 	plan skip_all => "Need sudo to test check_icmp";
 }