Python: Remove redundant inline casts

These are all implied by the return type of the other side of the
equality.

Author: tausbn

python/ql/lib/semmle/python/frameworks/Django.qll

@@ -1873,7 +1873,7 @@ module PrivateDjango {
     /** Gets a reference to this class. */
     private DataFlow::TypeTrackingNode getARef(DataFlow::TypeTracker t) {
       t.start() and
-      result.asExpr().(ClassExpr) = this.getParent()
+      result.asExpr() = this.getParent()
       or
       exists(DataFlow::TypeTracker t2 | result = this.getARef(t2).track(t2, t))
     }

python/ql/lib/semmle/python/frameworks/Flask.qll

@@ -193,7 +193,7 @@ module Flask {
 
     FlaskViewClass() {
       this.getABase() = Views::View::subclassRef().getAUse().asExpr() and
-      api_node.getAnImmediateUse().asExpr().(ClassExpr) = this.getParent()
+      api_node.getAnImmediateUse().asExpr() = this.getParent()
     }
 
     /** Gets a function that could handle incoming requests, if any. */
@@ -218,7 +218,7 @@ module Flask {
   class FlaskMethodViewClass extends FlaskViewClass {
     FlaskMethodViewClass() {
       this.getABase() = Views::MethodView::subclassRef().getAUse().asExpr() and
-      api_node.getAnImmediateUse().asExpr().(ClassExpr) = this.getParent()
+      api_node.getAnImmediateUse().asExpr() = this.getParent()
     }
 
     override Function getARequestHandler() {
@@ -299,7 +299,7 @@ module Flask {
     override Function getARequestHandler() {
       exists(DataFlow::LocalSourceNode func_src |
         func_src.flowsTo(this.getViewArg()) and
-        func_src.asExpr().(CallableExpr) = result.getDefinition()
+        func_src.asExpr() = result.getDefinition()
       )
       or
       exists(FlaskViewClass vc |

python/ql/lib/semmle/python/frameworks/Tornado.qll

@@ -102,7 +102,7 @@ private module Tornado {
           /** Gets a reference to this class. */
           private DataFlow::TypeTrackingNode getARef(DataFlow::TypeTracker t) {
             t.start() and
-            result.asExpr().(ClassExpr) = this.getParent()
+            result.asExpr() = this.getParent()
             or
             exists(DataFlow::TypeTracker t2 | result = this.getARef(t2).track(t2, t))
           }