Smack: remove unneeded NULL-termination from securtity label

Values of extended attributes are stored as binary blobs. NULL-termination
of them isn't required. It just wastes disk space and confuses command-line
tools like getfattr because they have to print that zero byte at the end.

This patch removes terminating zero byte from initial security label in
smack_inode_init_security and cuts it out in function smack_inode_getsecurity
which is used by syscall getxattr. This change seems completely safe, because
function smk_parse_smack ignores everything after first zero byte.

Signed-off-by: Konstantin Khlebnikov <k.khlebnikov@samsung.com>

security/smack/smack_lsm.c

@@ -672,7 +672,7 @@ static int smack_inode_init_security(struct inode *inode, struct inode *dir,
 	}
 
 	if (len)
-		*len = strlen(isp) + 1;
+		*len = strlen(isp);
 
 	return 0;
 }
@@ -1076,7 +1076,7 @@ static int smack_inode_getsecurity(const struct inode *inode,
 
 	if (strcmp(name, XATTR_SMACK_SUFFIX) == 0) {
 		isp = smk_of_inode(inode);
-		ilen = strlen(isp) + 1;
+		ilen = strlen(isp);
 		*buffer = isp;
 		return ilen;
 	}
@@ -1101,7 +1101,7 @@ static int smack_inode_getsecurity(const struct inode *inode,
 	else
 		return -EOPNOTSUPP;
 
-	ilen = strlen(isp) + 1;
+	ilen = strlen(isp);
 	if (rc == 0) {
 		*buffer = isp;
 		rc = ilen;