Redirect error message to stderr

Signed-off-by: Thomas Daubney <thomas.daubney@arm.com>
diff --git a/scripts/lcov.sh b/scripts/lcov.sh
index 15b13c1..2885537 100755
--- a/scripts/lcov.sh
+++ b/scripts/lcov.sh
@@ -35,7 +35,7 @@
 
 in_mbedtls_repo () {
     if [ ! -f $PROJECT_NAME_FILE ]; then
-        echo "$PROJECT_NAME_FILE does not exist... Exiting..."
+        echo "$PROJECT_NAME_FILE does not exist... Exiting..." >&2
         exit 1
     fi
     grep -Fxq "Mbed TLS" "$PROJECT_NAME_FILE"