gss_krb5: create a define for token header size and clean up ptr location

cleanup:
Document token header size with a #define instead of open-coding it.

Don't needlessly increment "ptr" past the beginning of the header
which makes the values passed to functions more understandable and
eliminates the need for extra "krb5_hdr" pointer.

Clean up some intersecting  white-space issues flagged by checkpatch.pl.

This leaves the checksum length hard-coded at 8 for DES.  A later patch
cleans that up.

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 5f1d36d..b8f42ef 100644
--- a/net/sunrpc/auth_gss/gss_krb5_seal.c
+++ b/net/sunrpc/auth_gss/gss_krb5_seal.c
@@ -78,7 +78,7 @@
 	struct krb5_ctx		*ctx = gss_ctx->internal_ctx_id;
 	char			cksumdata[16];
 	struct xdr_netobj	md5cksum = {.len = 0, .data = cksumdata};
-	unsigned char		*ptr, *krb5_hdr, *msg_start;
+	unsigned char		*ptr, *msg_start;
 	s32			now;
 	u32			seq_send;
 
@@ -87,36 +87,36 @@
 
 	now = get_seconds();
 
-	token->len = g_token_size(&ctx->mech_used, 24);
+	token->len = g_token_size(&ctx->mech_used, GSS_KRB5_TOK_HDR_LEN + 8);
 
 	ptr = token->data;
-	g_make_token_header(&ctx->mech_used, 24, &ptr);
+	g_make_token_header(&ctx->mech_used, GSS_KRB5_TOK_HDR_LEN + 8, &ptr);
 
-	*ptr++ = (unsigned char) ((KG_TOK_MIC_MSG>>8)&0xff);
-	*ptr++ = (unsigned char) (KG_TOK_MIC_MSG&0xff);
+	/* ptr now at header described in rfc 1964, section 1.2.1: */
+	ptr[0] = (unsigned char) ((KG_TOK_MIC_MSG >> 8) & 0xff);
+	ptr[1] = (unsigned char) (KG_TOK_MIC_MSG & 0xff);
 
-	/* ptr now at byte 2 of header described in rfc 1964, section 1.2.1: */
-	krb5_hdr = ptr - 2;
-	msg_start = krb5_hdr + 24;
+	msg_start = ptr + GSS_KRB5_TOK_HDR_LEN + 8;
 
-	*(__be16 *)(krb5_hdr + 2) = htons(SGN_ALG_DES_MAC_MD5);
-	memset(krb5_hdr + 4, 0xff, 4);
+	*(__be16 *)(ptr + 2) = htons(SGN_ALG_DES_MAC_MD5);
+	memset(ptr + 4, 0xff, 4);
 
-	if (make_checksum("md5", krb5_hdr, 8, text, 0, &md5cksum))
+	if (make_checksum("md5", ptr, 8, text, 0, &md5cksum))
 		return GSS_S_FAILURE;
 
 	if (krb5_encrypt(ctx->seq, NULL, md5cksum.data,
 			  md5cksum.data, md5cksum.len))
 		return GSS_S_FAILURE;
 
-	memcpy(krb5_hdr + 16, md5cksum.data + md5cksum.len - 8, 8);
+	memcpy(ptr + GSS_KRB5_TOK_HDR_LEN, md5cksum.data + md5cksum.len - 8, 8);
 
 	spin_lock(&krb5_seq_lock);
 	seq_send = ctx->seq_send++;
 	spin_unlock(&krb5_seq_lock);
 
 	if (krb5_make_seq_num(ctx->seq, ctx->initiate ? 0 : 0xff,
-			      seq_send, krb5_hdr + 16, krb5_hdr + 8))
+			      seq_send, ptr + GSS_KRB5_TOK_HDR_LEN,
+			      ptr + 8))
 		return GSS_S_FAILURE;
 
 	return (ctx->endtime < now) ? GSS_S_CONTEXT_EXPIRED : GSS_S_COMPLETE;