Fixing an invalid test

Putting the attribute after the declarator has different behavior than
putting it before or on the type itself; the expected diagnostics were
not triggered.

This was caught by precommit CI. My local testing did not catch it
because I was accidentally testing noderef.c instead of noderef.cpp.

This removes the expected diagnostics and just leaves in the "does not
crash" test.

Author: AaronBallman

clang/test/Frontend/noderef.cpp

@@ -186,6 +186,5 @@ const int *const_cast_check(NODEREF int *x) {
 
 namespace GH116124 {
 // This declaration would previously cause a failed assertion.
-int *_Atomic a __attribute__((noderef)); // expected-note {{declared here}}
-int x = *a;                              // expected-warning{{dereferencing a; was declared with a 'noderef' type}}
+int *_Atomic a __attribute__((noderef));
 }