backwards memcpy

Index: io/hpmud/musb.c
--- io/hpmud/musb.c.orig
+++ io/hpmud/musb.c
@@ -776,7 +776,7 @@ static int device_id(int fd, unsigned char *buffer, in
         len = size-1;   /* leave byte for zero termination */
     if (len > 2)
         len -= 2;
-    memcpy(buffer, buffer+2, len);    /* remove length */
+    memmove(buffer, buffer+2, len);    /* remove length */
     buffer[len]=0;
     DBG("read actual device_id successfully fd=%d len=%d\n", fd, len);
 
@@ -1263,7 +1263,7 @@ enum HPMUD_RESULT __attribute__ ((visibility ("hidden"
 
     if (*len)
     {
-        memcpy(buf, pd->id, *len > size ? size : *len);
+        memmove(buf, pd->id, *len > size ? size : *len);
         stat = HPMUD_R_OK;
     }