Some more clippy warning fixes

[rustfix](https://github.com/killercup/rustfix) makes it much easier.

pyo3cls/src/py_class.rs

@@ -151,7 +151,7 @@ fn impl_class(cls: &syn::Ident, base: &syn::Ident,
                                 <#cls as _pyo3::typeob::PyTypeObject>::init_type(
                                     _pyo3::Python::assume_gil_acquired());
                             }
-                            std::mem::transmute(FREELIST)
+                            &mut *FREELIST
                         }
                     }
                 }

src/class/methods.rs

@@ -101,7 +101,7 @@ impl PyGetterDef {
             dst.name = CString::new(self.name).expect(
                 "Method name must not contain NULL byte").into_raw();
         }
-        dst.get = Some(self.meth.clone());
+        dst.get = Some(self.meth);
     }
 }
 

src/object.rs

@@ -213,7 +213,7 @@ impl AsPyRef<PyObjectRef> for PyObject {
     }
     #[inline]
     fn as_mut(&self, _py: Python) -> &mut PyObjectRef {
-        unsafe {std::mem::transmute(self as *const _ as *mut PyObjectRef)}
+        unsafe {&mut *(self as *const _ as *mut PyObjectRef)}
     }
 }
 

src/pythonrun.rs

@@ -216,7 +216,7 @@ pub unsafe fn register_pointer(obj: *mut ffi::PyObject)
 
 pub unsafe fn register_owned(_py: Python, obj: *mut ffi::PyObject) -> &PyObjectRef
 {
-    let pool: &'static mut Pointers = mem::transmute(POINTERS);
+    let pool: &'static mut Pointers = &mut *POINTERS;
     pool.owned.push(obj);
     mem::transmute(&pool.owned[pool.owned.len()-1])
 }

tests/test_class.rs

@@ -225,13 +225,13 @@ fn data_is_dropped() {
             member2: TestDropCall { drop_called: drop_called2.clone() },
             token: t
         }).unwrap();
-        assert!(drop_called1.load(Ordering::Relaxed) == false);
-        assert!(drop_called2.load(Ordering::Relaxed) == false);
+        assert!(!drop_called1.load(Ordering::Relaxed));
+        assert!(!drop_called2.load(Ordering::Relaxed));
         drop(inst);
     }
 
-    assert!(drop_called1.load(Ordering::Relaxed) == true);
-    assert!(drop_called2.load(Ordering::Relaxed) == true);
+    assert!(drop_called1.load(Ordering::Relaxed));
+    assert!(drop_called2.load(Ordering::Relaxed));
 }
 
 #[py::class]