tty: serial: Remove call to memset after pci_alloc_consistent

pci_alloc_consistent calls dma_alloc_coherent directly.
In commit 518a2f1925
("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 <huangfq.daxian@gmail.com>
Link: https://lore.kernel.org/r/20190715032001.7212-1-huangfq.daxian@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/tty/serial/icom.c

@@ -207,8 +207,6 @@ static int get_port_memory(struct icom_port *icom_port)
 		return -ENOMEM;
 	}
 
-	memset(icom_port->statStg, 0, 4096);
-
 	/* FODs: Frame Out Descriptor Queue, this is a FIFO queue that
            indicates that frames are to be transmitted
 	*/