Fix the typo in the file

Change-Id: I3a3976bdab6743f6d741d39708b01eacf6a01074
diff --git a/tools/xen/install_os_domU.sh b/tools/xen/install_os_domU.sh
index 3a61215..66b9eda 100755
--- a/tools/xen/install_os_domU.sh
+++ b/tools/xen/install_os_domU.sh
@@ -247,7 +247,7 @@
 fi
 
 if [ -n "${EXIT_AFTER_JEOS_INSTALLATION:-}" ]; then
-    echo "User requested to quit after JEOS instalation"
+    echo "User requested to quit after JEOS installation"
     exit 0
 fi