gianfar: fix babbling rx error event bug

Gianfar interrupt handler uses IEVENT_ERR_MASK to check and handle errors.
Babbling RX error (IEVENT_BABR) should be included in IEVENT_ERROR_MASK.
Otherwise if BABR is raised, it never gets handled nor cleared, and an
interrupt storm results. This has been observed to happen on sending a
burst of ethernet frames to a gianfar based board.

Signed-off-by: Xiaotian Feng <xiaotian.feng@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/gianfar.h

@@ -259,7 +259,7 @@ extern const char gfar_driver_version[];
 (IEVENT_RXC | IEVENT_BSY | IEVENT_EBERR | IEVENT_MSRO | \
  IEVENT_BABT | IEVENT_TXC | IEVENT_TXE | IEVENT_LC \
  | IEVENT_CRL | IEVENT_XFUN | IEVENT_DPE | IEVENT_PERR \
- | IEVENT_MAG)
+ | IEVENT_MAG | IEVENT_BABR)
 
 #define IMASK_INIT_CLEAR	0x00000000
 #define IMASK_BABR              0x80000000