amd/agesa/f1?/Lib/amdlib.c: Integer overflow in loop construct

The semantics of this loop relies on an integer overflow in Index >=0
that implies a return value of (UINT8)-1 which around wraps to 0xFF, or
VOLT_UNSUPPORTED.

Change-Id: I44d68973d0a80093350b2a8a4d3b46bfbb57917a
Signed-off-by: Edward O'Callaghan <eocallaghan@alterapraxis.com>
Reviewed-on: http://review.coreboot.org/5801
Tested-by: build bot (Jenkins)
Reviewed-by: Marc Jones <marc.jones@se-eng.com>
5 files changed