video: fbdev-MMP: Remove call to memset after dma_alloc_coherent

In commit 518a2f1925c3
("dma-mapping: zero memory returned from dma_alloc_*"),
dma_alloc_coherent has already zeroed the memory.
So memset is not needed.

Signed-off-by: Fuqian Huang <[e-mail]>
Reviewed-by: Emil Velikov <[e-mail]>
Signed-off-by: Bartlomiej Zolnierkiewicz <[e-mail]>
Link: https://patchwork.freedesktop.org/patch/msgid/[e-mail]

drivers/video/fbdev/mmp/fb/mmpfb.c

···
 		ret = -ENOMEM;
 		goto failed_destroy_mutex;
 	}
-	memset(fbi->fb_start, 0, fbi->fb_size);
 	dev_info(fbi->dev, "fb %dk allocated\n", fbi->fb_size/1024);
 
 	/* fb power on */