!14 fix mdmonitor.service start failed

From: @wguanghao
Reviewed-by: @wubo009
Signed-off-by: @volcanodragon

mdadm.spec

@@ -1,6 +1,6 @@
 Name:     mdadm
 Version:  4.1
-Release:  3
+Release:  4
 Summary:  The software RAID arrays user manage tools
 License:  GPLv2+
 URL:      http://www.kernel.org/pub/linux/utils/raid/mdadm/
@@ -99,6 +99,9 @@ install -d -m 710 %{buildroot}/var/run/mdadm/
 %{_mandir}/man*/*
 
 %changelog
+* Thu Sep 24 2020 wuguanghao <wuguanghao3@huawei.com> - 4.1-4
+- fix mdmonitor.service start failed 
+
 * Mon Jul 13 2020 Zhiqiang Liu <lzhq28@mail.ustc.edu.cn> - 4.1-3
 - backport upstream bugfix patches
 

mdmonitor.service

@@ -16,6 +16,7 @@ Type=forking
 PIDFile=/run/mdadm/mdadm.pid
 Environment=  MDADM_MONITOR_ARGS="--scan --syslog"
 EnvironmentFile=-/etc/sysconfig/mdadm
+ExecStartPre= mkdir -p /run/mdadm
 ExecStart=/sbin/mdadm --monitor $MDADM_MONITOR_ARGS -f --pid-file=/run/mdadm/mdadm.pid
 
 [Install]