tool_getparam: use UNITTEST not, ifdef

Closes #20174

src/tool_getparam.c

@@ -377,10 +377,11 @@ static const struct LongShort aliases[]= {
 /* Split the argument of -E to 'certname' and 'passphrase' separated by colon.
  * We allow ':' and '\' to be escaped by '\' so that we can use certificate
  * nicknames containing ':'. See <https://sourceforge.net/p/curl/bugs/1196/>
- * for details. */
-#ifndef UNITTESTS
-static
-#endif
+ * for details.
+ *
+ * Unit test 1394
+ */
+UNITTEST
 ParameterError parse_cert_parameter(const char *cert_parameter,
                                     char **certname,
                                     char **passphrase)