wimax: misplaced parenthesis

Fix misplaced parenthesis
Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
Signed-off-by: Inaky Perez-Gonzalez <inaky@linux.intel.com>

drivers/net/wimax/i2400m/tx.c

@@ -310,7 +310,7 @@ size_t __i2400m_tx_tail_room(struct i2400m *i2400m)
 	size_t tail_room;
 	size_t tx_in;
 
-	if (unlikely(i2400m->tx_in) == 0)
+	if (unlikely(i2400m->tx_in == 0))
 		return I2400M_TX_BUF_SIZE;
 	tx_in = i2400m->tx_in % I2400M_TX_BUF_SIZE;
 	tail_room = I2400M_TX_BUF_SIZE - tx_in;