Fix off-by-one error in #line directives

The line number is the number of the next line.

Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
diff --git a/tests/suites/helpers.function b/tests/suites/helpers.function
index 7aa614a..d611e72 100644
--- a/tests/suites/helpers.function
+++ b/tests/suites/helpers.function
@@ -1,4 +1,4 @@
-#line 1 "helpers.function"
+#line 2 "helpers.function"
 /*----------------------------------------------------------------------------*/
 /* Headers */