Fix arity of the PARAM_FAILED() macro and function

It was inconsistent between files: sometimes 3 arguments, sometimes one.

Align to 1 argument for the macro and 3 for the function, because:
- we don't need 3 arguments for the macro, it can add __FILE__ and __LINE__
  in its expansion, while the function needs them as parameters to be correct;
- people who re-defined the macro should have flexibility, and 3 arguments
  can give the impression they they don't have as much as they actually do;
- the design document has the macro with 1 argument, so let's stick to that.
diff --git a/tests/suites/helpers.function b/tests/suites/helpers.function
index 3ae5471..4b9513f 100644
--- a/tests/suites/helpers.function
+++ b/tests/suites/helpers.function
@@ -25,7 +25,7 @@
 
 #if defined(MBEDTLS_CHECK_PARAMS)
 #include <setjmp.h>
-#define MBEDTLS_PARAM_FAILED(x)    mbedtls_param_failed( #x )
+#define MBEDTLS_PARAM_FAILED(x)    mbedtls_param_failed( #x, __FILE__, __LINE__ )
 
 #endif /* MBEDTLS_CHECK_PARAMS */