sanity: add new line when emitting an error

Change-Id: I4075dbe3706b45e926e9ab4d0f620fe262aaa705
Signed-off-by: Anas Nashif <anas.nashif@intel.com>

scripts/sanitycheck

diff --git a/scripts/sanitycheck b/scripts/sanitycheck
index d107c74..52b06b4 100755
--- a/scripts/sanitycheck
+++ b/scripts/sanitycheck
@@ -94,7 +94,7 @@
 import csv
 
 if "ZEPHYR_BASE" not in os.environ:
-    sys.stderr.write("$ZEPHYR_BASE environment variable undefined")
+    sys.stderr.write("$ZEPHYR_BASE environment variable undefined.\n")
     exit(1)
 ZEPHYR_BASE = os.environ["ZEPHYR_BASE"]
 VERBOSE = 0