defect 3186: check the existence of vncviewer

git-svn-id: https://svn.code.sf.net/p/xcat/code/xcat-core/trunk@14469 8638fb3e-16cb-4fca-ae20-7b5d299a9bcd

xCAT-client/share/xcat/rvid/rvid.kvm

@@ -9,6 +9,10 @@ if [ ! -z "$rvid_virturi" -a ! -z "$rvid_virtname" ]; then
 fi
 myport=${rvid_vidport#*:}
 if [ $rvid_vidproto = "vnc" ];then
+    if [ ! -x "/usr/bin/vncviewer" ]; then
+        echo "Error: vncviewer could not be found and needed for this VM." >&2;
+        exit 1
+    fi
 	let myport=myport-5900;
 	export VNC_VIA_CMD='/usr/bin/ssh -o BatchMode=yes -f -L "$L":"$H":"$R" "$G" sleep 20'
 	(