Remove a redundant string length check and variable assignment.

Found with Clang's static analyzer.

Modules/cPickle.c

@@ -903,7 +903,6 @@ whichmodule(PyObject *global, PyObject *global_name)
 	   like this rule. jlf
 	*/
 	if (!j) {
-		j=1;
 		name=__main___str;
 	}
 
@@ -1235,9 +1234,6 @@ save_string(Picklerobject *self, PyObject *args, int doput)
 		int i;
 		char c_str[5];
 
-		if ((size = PyString_Size(args)) < 0)
-			return -1;
-
 		if (size < 256) {
 			c_str[0] = SHORT_BINSTRING;
 			c_str[1] = size;