sm501: Fix warning about unreachable code

Coverity warned that the false arm of conditional expression is
unreachable when it is inside an if with the same condition.
Remove the unreachable code to avoid the warning.

Fixes: CID 1394215
Reported-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NBALATON Zoltan <balaton@eik.bme.hu>
Reviewed-by: NPhilippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: NDavid Gibson <david@gibson.dropbear.id.au>

hw/display/sm501.c

@@ -1024,7 +1024,7 @@ static void sm501_i2c_write(void *opaque, hwaddr addr, uint64_t value,
                         if (res) {
                             SM501_DPRINTF("sm501 i2c : transfer failed"
                                           " i=%d, res=%d\n", i, res);
-                            s->i2c_status |= (res ? SM501_I2C_STATUS_ERROR : 0);
+                            s->i2c_status |= SM501_I2C_STATUS_ERROR;
                             return;
                         }
                     }