Remove define for KRB5_CKSUM_LENGTH, which will become enctype-dependent

cleanup: When adding new encryption types, the checksum length
can be different for each enctype.  Face the fact that the
current code only supports DES which has a checksum length of 8.

Signed-off-by: Kevin Coffman <kwc@citi.umich.edu>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
diff --git a/net/sunrpc/auth_gss/gss_krb5_seal.c b/net/sunrpc/auth_gss/gss_krb5_seal.c
index dedcbd61..39c08b7 100644
--- a/net/sunrpc/auth_gss/gss_krb5_seal.c
+++ b/net/sunrpc/auth_gss/gss_krb5_seal.c
@@ -109,8 +109,7 @@
 			  md5cksum.data, md5cksum.len))
 		return GSS_S_FAILURE;
 
-	memcpy(krb5_hdr + 16, md5cksum.data + md5cksum.len - KRB5_CKSUM_LENGTH,
-	       KRB5_CKSUM_LENGTH);
+	memcpy(krb5_hdr + 16, md5cksum.data + md5cksum.len - 8, 8);
 
 	spin_lock(&krb5_seq_lock);
 	seq_send = ctx->seq_send++;