Fixed compile-firm tests

They should expect the compiled to be name `a.out`

mjtest/test/exec_tests.py

@@ -111,7 +111,7 @@ class JavaExecTest(BasicSyntaxTest):
                 os.chdir(cwd)
                 raise
             try:
-                out, err, rtcode = self.env.run_command("./" + base_filename, timeout=timeout)
+                out, err, rtcode = self.env.run_command("./a.out", timeout=timeout)
                 if rtcode != 0:
                     test_result.incorrect_msg = "binary can't be run, non zero error code"
                     test_result.set_error_code(rtcode)
@@ -198,7 +198,7 @@ class JavaInfiniteLoopTest(BasicSyntaxTest):
                 test_result.add_file("Source file", self.preprocessed_file)
                 os.chdir(cwd)
                 return test_result
-            out, err, rtcode = self.env.run_command("./" + base_filename, timeout=timeout)
+            out, err, rtcode = self.env.run_command("./a.out", timeout=timeout)
             if rtcode != 0:
                 test_result.incorrect_msg = "binary can't be run, non zero error code"
                 test_result.set_error_code(rtcode)