cxgb4: Add llseek operation for flash debugfs entry

Signed-off-by: Hariprasad Shenai <hariprasad@chelsio.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/chelsio/cxgb4/cxgb4_debugfs.c

@@ -1572,6 +1572,7 @@ static const struct file_operations flash_debugfs_fops = {
 	.owner   = THIS_MODULE,
 	.open    = mem_open,
 	.read    = flash_read,
+	.llseek  = default_llseek,
 };
 
 static inline void tcamxy2valmask(u64 x, u64 y, u8 *addr, u64 *mask)