usb: host: Remove call to memset after dma_alloc_coherent

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/20190715032010.7258-1-huangfq.daxian@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/host/xhci-dbgcap.c

@@ -22,7 +22,6 @@ dbc_dma_alloc_coherent(struct xhci_hcd *xhci, size_t size,
 
 	vaddr = dma_alloc_coherent(xhci_to_hcd(xhci)->self.sysdev,
 				   size, dma_handle, flags);
-	memset(vaddr, 0, size);
 	return vaddr;
 }
 

drivers/usb/host/xhci-mem.c

@@ -2399,7 +2399,6 @@ int xhci_mem_init(struct xhci_hcd *xhci, gfp_t flags)
 			flags);
 	if (!xhci->dcbaa)
 		goto fail;
-	memset(xhci->dcbaa, 0, sizeof *(xhci->dcbaa));
 	xhci->dcbaa->dma = dma;
 	xhci_dbg_trace(xhci, trace_xhci_dbg_init,
 			"// Device context base array address = 0x%llx (DMA), %p (virt)",