Cleanup: quiet pylint's inconsistent-return-statements warning

No functional changes as the return value either relied on None
evaluating to False or wasn't used.

scripts/startup/bl_operators/clip.py

@@ -488,7 +488,7 @@ class CLIP_OT_constraint_to_fcurve(Operator):
                 efra = max(efra, track.markers[-1].frame)
 
         if sfra is None or efra is None:
-            return
+            return {'CANCELLED'}
 
         # Store object matrices.
         for x in range(sfra, efra + 1):
@@ -516,6 +516,8 @@ class CLIP_OT_constraint_to_fcurve(Operator):
 
         scene.frame_set(frame_current)
 
+        return {'FINISHED'}
+
     def execute(self, context):
         scene = context.scene
         # XXX, should probably use context.selected_editable_objects

scripts/startup/bl_ui/properties_physics_common.py

@@ -37,6 +37,7 @@ def physics_add(layout, md, name, type, typeicon, toggles):
             text_ctxt=i18n_contexts.default,
             icon=typeicon,
         ).type = type
+        return None
 
 
 def physics_add_special(layout, data, name, addop, removeop, typeicon):

scripts/startup/bl_ui/properties_physics_fluid.py

@@ -82,8 +82,7 @@ class PhysicButtonsPanel:
 
         md = context.fluid
         flow = md.flow_settings
-        if (flow.flow_behavior == 'OUTFLOW'):
-            return True
+        return (flow.flow_behavior == 'OUTFLOW')
 
     @staticmethod
     def poll_fluid_flow_liquid(context):
@@ -92,8 +91,7 @@ class PhysicButtonsPanel:
 
         md = context.fluid
         flow = md.flow_settings
-        if (flow.flow_type == 'LIQUID'):
-            return True
+        return (flow.flow_type == 'LIQUID')
 
 
 class PHYSICS_PT_fluid(PhysicButtonsPanel, Panel):

scripts/startup/bl_ui/space_clip.py

@@ -1079,10 +1079,11 @@ class CLIP_PT_2d_cursor(Panel):
 
     @classmethod
     def poll(cls, context):
-        sc = context.space_data
+        if not CLIP_PT_clip_view_panel.poll(context):
+            return False
 
-        if CLIP_PT_clip_view_panel.poll(context):
-            return sc.pivot_point == 'CURSOR' or sc.mode == 'MASK'
+        sc = context.space_data
+        return sc.pivot_point == 'CURSOR' or sc.mode == 'MASK'
 
     def draw(self, context):
         layout = self.layout

scripts/startup/bl_ui/space_toolsystem_toolbar.py

@@ -451,6 +451,7 @@ class _defs_view3d_add:
             for item in km.keymap_items:
                 if item.propvalue == propvalue:
                     return item
+            return None
 
         if km is not None:
             kmi_snap = keymap_item_from_propvalue('SNAP_ON')

scripts/startup/bl_ui/space_view3d.py

@@ -569,6 +569,8 @@ class _draw_tool_settings_context_mode:
         elif curves_tool == "SLIDE":
             layout.popover("VIEW3D_PT_tools_brush_falloff")
 
+        return True
+
 
 class VIEW3D_HT_header(Header):
     bl_space_type = 'VIEW_3D'