Initialize the date in log_param_time

I was getting initialization problems from the initialized date in the
`log_param_date_as_time` test, so this includes an initialization step.

Previously, random(?) values would fill the `ticks` field, which left
the zero-tick case uncovered (usually).  This removes that problem.

src/framework/unit_tests/MOM_file_parser_tests.F90

@@ -1305,6 +1305,7 @@ subroutine test_log_param_time_as_date
   close(param_unit)
 
   call open_param_file(param_filename, param)
+  sample = set_date(1980, 1, 1, 0, 0, 0)
   call log_param(param, module_name, sample_param_name, sample, desc=desc, &
       log_date=.true.)
   call close_param_file(param)