staging: dgnc: delete all references to 'flipbuf'

This patch deletes all references to 'flipbuf'.Memory is allocated and
freed but never used anywhere in the driver.Also deleted an ununsed
Macro defined in the header file.

Signed-off-by: Gujulan Elango Hari Prasath <[e-mail]>
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/staging/dgnc/dgnc_driver.c

···
 		}
 	}
 
-	kfree(brd->flipbuf);
 
 	dgnc_Board[brd->boardnum] = NULL;
 
···
 	kfree(brd->msgbuf_head);
 	brd->msgbuf_head = NULL;
 	spin_unlock_irqrestore(&dgnc_global_lock, flags);
-
-	/*
-	 * allocate flip buffer for board.
-	 *
-	 * Okay to malloc with GFP_KERNEL, we are not at interrupt
-	 * context, and there are no locks held.
-	 */
-	brd->flipbuf = kzalloc(MYFLIPLEN, GFP_KERNEL);
 
 	wake_up_interruptible(&brd->state_wait);
 

drivers/staging/dgnc/dgnc_driver.h

···
 
 	uint		TtyRefCnt;
 
-	char		*flipbuf;	/* Our flip buffer, alloced if board is found */
-
 	u16		dpatype;	/* The board "type", as defined by DPA */
 	u16		dpastatus;	/* The board "status", as defined by DPA */
 
···
 #define CH_TX_FIFO_LWM  0x0800		/* TX Fifo is below Low Water	*/
 #define CH_BREAK_SENDING 0x1000		/* Break is being sent		*/
 #define CH_LOOPBACK 0x2000		/* Channel is in lookback mode	*/
-#define CH_FLIPBUF_IN_USE 0x4000	/* Channel's flipbuf is in use	*/
 #define CH_BAUD0	0x08000		/* Used for checking B0 transitions */
 #define CH_FORCED_STOP  0x20000		/* Output is forcibly stopped	*/
 #define CH_FORCED_STOPI 0x40000		/* Input is forcibly stopped	*/