rt2x00: fix typo in rt2800.h

Fix a typo in a comment in rt2800.h. Instead of replacing the wrong
hexvalue (0x171c) with the correct one (0x1718) just use the appropriate
readable define.
Signed-off-by: Helmut Schaa <helmut.schaa@googlemail.com>
Acked-by: Ivo van Doorn <IvDoorn@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/rt2x00/rt2800.h

@@ -107,7 +107,7 @@
 /*
  * INT_SOURCE_CSR: Interrupt source register.
  * Write one to clear corresponding bit.
- * TX_FIFO_STATUS: FIFO Statistics is full, sw should read 0x171c
+ * TX_FIFO_STATUS: FIFO Statistics is full, sw should read TX_STA_FIFO
  */
 #define INT_SOURCE_CSR			0x0200
 #define INT_SOURCE_CSR_RXDELAYINT	FIELD32(0x00000001)