Revert r61779 - It undid correct code and caused test_zlib to fail on all
platforms with a 64-bit long.

The Alpha/Tru64 test problem is a problem in either tarfile or test_tarfile,
not zlib.

crc32 and adler32 return 32-bit values.  by using a long thats larger than
32-bits in these functions they were prevented from wrapping around to their
signed 32-bit value that we want them to return in python 2.x.
diff --git a/Modules/zlibmodule.c b/Modules/zlibmodule.c
index a15f2d9..384399d 100644
--- a/Modules/zlibmodule.c
+++ b/Modules/zlibmodule.c
@@ -891,8 +891,7 @@
 {
     uLong adler32val = adler32(0L, Z_NULL, 0);
     Byte *buf;
-    int len;
-    long signed_val;
+    int len, signed_val;
 
     if (!PyArg_ParseTuple(args, "s#|k:adler32", &buf, &len, &adler32val))
 	return NULL;
@@ -915,8 +914,7 @@
 {
     uLong crc32val = crc32(0L, Z_NULL, 0);
     Byte *buf;
-    int len;
-    long signed_val;
+    int len, signed_val;
 
     if (!PyArg_ParseTuple(args, "s#|k:crc32", &buf, &len, &crc32val))
 	return NULL;