eCryptfs: Remove unnecessary casts when parsing packet lengths

The elements in the data array are already unsigned chars and do not
need to be casted.
Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>

fs/ecryptfs/keystore.c

@@ -100,12 +100,12 @@ int ecryptfs_parse_packet_length(unsigned char *data, size_t *size,
 	(*size) = 0;
 	if (data[0] < 192) {
 		/* One-byte length */
-		(*size) = (unsigned char)data[0];
+		(*size) = data[0];
 		(*length_size) = 1;
 	} else if (data[0] < 224) {
 		/* Two-byte length */
-		(*size) = (((unsigned char)(data[0]) - 192) * 256);
-		(*size) += ((unsigned char)(data[1]) + 192);
+		(*size) = (data[0] - 192) * 256;
+		(*size) += data[1] + 192;
 		(*length_size) = 2;
 	} else if (data[0] == 255) {
 		/* If support is added, adjust ECRYPTFS_MAX_PKT_LEN_SIZE */