MIPS: BCM47xx: Use kmemdup rather than duplicating its implementation

The patch was generated using fixed coccinelle semantic patch
scripts/coccinelle/api/memdup.cocci [1].

[1]: http://permalink.gmane.org/gmane.linux.kernel/2014320

Signed-off-by: Andrzej Hajda <[e-mail]>
Acked-by: Hauke Mehrtens <[e-mail]>
Cc: Hauke Mehrtens <[e-mail]>
Cc: Rafał Miłecki <[e-mail]>
Cc: Andrzej Hajda <[e-mail]>
Cc: Bartlomiej Zolnierkiewicz <[e-mail]>
Cc: Marek Szyprowski <[e-mail]>
Cc: [e-mail]
Cc: [e-mail]
Patchwork: https://patchwork.linux-mips.org/patch/10898/
Signed-off-by: Ralf Baechle <[e-mail]>

arch/mips/bcm47xx/buttons.c

···
 {
 	size_t size = nbuttons * sizeof(*buttons);
 
-	bcm47xx_button_pdata.buttons = kmalloc(size, GFP_KERNEL);
+	bcm47xx_button_pdata.buttons = kmemdup(buttons, size, GFP_KERNEL);
 	if (!bcm47xx_button_pdata.buttons)
 		return -ENOMEM;
-	memcpy(bcm47xx_button_pdata.buttons, buttons, size);
 	bcm47xx_button_pdata.nbuttons = nbuttons;
 
 	return 0;