Factor-out the common code for setting a KeyError.

Objects/setobject.c

@@ -11,20 +11,6 @@
 #include "structmember.h"
 #include "stringlib/eq.h"
 
-/* Set a key error with the specified argument, wrapping it in a
- * tuple automatically so that tuple keys are not unpacked as the
- * exception arguments. */
-static void
-set_key_error(PyObject *arg)
-{
-    PyObject *tup;
-    tup = PyTuple_Pack(1, arg);
-    if (!tup)
-        return; /* caller will expect error to be set anyway */
-    PyErr_SetObject(PyExc_KeyError, tup);
-    Py_DECREF(tup);
-}
-
 /* This must be >= 1. */
 #define PERTURB_SHIFT 5
 #define LINEAR_PROBES 9
@@ -1948,7 +1934,7 @@ set_remove(PySetObject *so, PyObject *key)
     }
 
     if (rv == DISCARD_NOTFOUND) {
-        set_key_error(key);
+        _PyErr_SetKeyError(key);
         return NULL;
     }
     Py_RETURN_NONE;