specify course_id in all StudentModule 'get' calls

StudentModule specifies student, course id, and module state key must
all be unique together. The reset code in module_tree_reset was calling
get without specifying course_id which means if two courses (with
different course ids) share the same users and module state keys then
calling StudentModule.objects.get with only the student and module state
key raises an error for users that tried both courses. Specifying all
unique_together fields fixes the issue.

lms/djangoapps/courseware/module_tree_reset.py

@@ -18,7 +18,8 @@ log = logging.getLogger("mitx.module_tree_reset")
 
 
 class TreeNode(object):
-    def __init__(self, module, level, student):
+    def __init__(self, course_id, module, level, student):
+        self.course_id = course_id
         self.module = module
         self.level = level
         self.student = student
@@ -26,6 +27,7 @@ class TreeNode(object):
         if self.module.category in ['randomize', 'problem', 'problemset']:
             try:
                 self.smstate = StudentModule.objects.get(
+                    course_id=self.course_id,
                     module_state_key=str(self.module.location),
                     student=student)
             except StudentModule.DoesNotExist:
@@ -52,7 +54,7 @@ class TreeNodeSet(list):
         self.get_modules_to_reset()
 
     def get_tree(self, module, ms, level=1):
-        self.append(TreeNode(module, level, self.student))
+        self.append(TreeNode(self.course_id, module, level, self.student))
         for child in getattr(module, 'children', []):
             m = ms.get_instance(self.course_id, child)
             if m is not None:
@@ -197,6 +199,7 @@ class ProctorModuleInfo(object):
             try:
                 sm = StudentModule.objects.get(
                     module_state_key=str(rpmod.ra_rand.location),
+                    course_id=self.course.id,
                     student=student)  # randomize state
             except StudentModule.DoesNotExist:
                 sm = StateInfo()
@@ -204,6 +207,7 @@ class ProctorModuleInfo(object):
             try:
                 ps_sm = StudentModule.objects.get(
                     module_state_key=str(rpmod.ra_ps.location),
+                    course_id=self.course.id,
                     student=student)  # problemset state
             except StudentModule.DoesNotExist:
                 ps_sm = StateInfo()