Fix misspellings in devstack

Fix misspellings detected by:
 * pip install misspellings
 * git ls-files | grep -v locale | misspellings -f -

Change-Id: I19726438d15cd27b813504aac530e7e53c4def12
Closes-Bug: #1257295
diff --git a/tools/xen/xenrc b/tools/xen/xenrc
index cd28234..b355a10 100644
--- a/tools/xen/xenrc
+++ b/tools/xen/xenrc
@@ -35,7 +35,7 @@
 GUEST_PASSWORD=${GUEST_PASSWORD:-secrete}
 
 # Extracted variables for OpenStack VM network device numbers.
-# Make sure, they form a continous sequence starting from 0
+# Make sure they form a continuous sequence starting from 0
 MGT_DEV_NR=0
 VM_DEV_NR=1
 PUB_DEV_NR=2