[lldb/Test] Generate YAML binary in build directory

Although it's not entirely clear to me why, this test was generating its
binary in the source directory instead of the build directory. This
patch fixes that following the same approach as other tests.

lldb/test/API/functionalities/show_location/TestShowLocationDwarf5.py

@@ -14,17 +14,9 @@ class TestTargetSourceMap(TestBase):
     def test_source_map(self):
         # Set the target soure map to map "./" to the current test directory.
         yaml_path = os.path.join(self.getSourceDir(), "a.yaml")
-        yaml_base, ext = os.path.splitext(yaml_path)
-        obj_path = self.getBuildArtifact(yaml_base)
+        obj_path = self.getBuildArtifact('a.out')
         self.yaml2obj(yaml_path, obj_path)
 
-        def cleanup():
-            if os.path.exists(obj_path):
-                os.unlink(obj_path)
-
-        # Execute the cleanup function during test case tear down.
-        self.addTearDownHook(cleanup)
-
         # Create a target with the object file we just created from YAML
         target = self.dbg.CreateTarget(obj_path)