mfd: dln2: Add a limit check for invalid echo
mfd: dln2: Add a limit check for invalid echo

The echo field in dln2_transfer_complete comes directly from an USB
transfer and we should not trust it is valid.

Reported-by: Dan Carpenter <ff341aa343d564f9e53e9dcb6996be8c04859a66@oracle.com>
Signed-off-by: Octavian Purdila <77c06d0261d8d3a9171f87dd4ca9bbbd1924db77@intel.com>
Signed-off-by: Lee Jones <630e34333487a351a857f6b705e04d30b37c1629@linaro.org>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs