[PATCH] usb-serial: Fix data corruption with usb serial emulation

* Remove the unused send_buf variable and its constant.

* Fix a math error
  The variables recv_ptr and recv_used are not large enough to hold
  the constant 384, which causes data corruption when the pointer is
  reset with: s->recv_ptr = (s->recv_ptr + len) % RECV_BUF;
Signed-off-by: NJason Wessel <jason.wessel@windriver.com>
Acked-by: NSamuel Thibault <samuel.thibault@ens-lyon.org>
Signed-off-by: NAurelien Jarno <aurelien@aurel32.net>

git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5242 c046a42c-6fe2-441c-8c8c-71466251a162

hw/usb-serial.c

@@ -22,7 +22,6 @@ do { printf("usb-serial: " fmt , ##args); } while (0)
 #endif
 
 #define RECV_BUF 384
-#define SEND_BUF 128        // Not used for now
 
 /* Commands */
 #define FTDI_RESET		0
@@ -94,9 +93,8 @@ typedef struct {
     uint16_t vendorid;
     uint16_t productid;
     uint8_t recv_buf[RECV_BUF];
-    uint8_t recv_ptr;
-    uint8_t recv_used;
-    uint8_t send_buf[SEND_BUF];
+    uint16_t recv_ptr;
+    uint16_t recv_used;
     uint8_t event_chr;
     uint8_t error_chr;
     uint8_t event_trigger;