From: Adrian Bunk <bunk@stusta.de>

This patch fixes an obvious check-after-dereference spotted by the Coverity
checker.

Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
---

 drivers/usb/serial/mos7840.c |    3 ++-
 1 files changed, 2 insertions(+), 1 deletion(-)

diff -puN drivers/usb/serial/mos7840.c~drivers-usb-serial-mos7840c-fix-a-check-after-dereference drivers/usb/serial/mos7840.c
--- a/drivers/usb/serial/mos7840.c~drivers-usb-serial-mos7840c-fix-a-check-after-dereference
+++ a/drivers/usb/serial/mos7840.c
@@ -2412,11 +2412,12 @@ static int mos7840_ioctl(struct usb_seri
 	}
 
 	mos7840_port = mos7840_get_port_private(port);
-	tty = mos7840_port->port->tty;
 
 	if (mos7840_port == NULL)
 		return -1;
 
+	tty = mos7840_port->port->tty;
+
 	dbg("%s - port %d, cmd = 0x%x", __FUNCTION__, port->number, cmd);
 
 	switch (cmd) {
_