x86, cpu: Fix regression in AMD errata checking code

x86, cpu: Fix regression in AMD errata checking code

commit 07a7795ca2e6e66d00b184efb46bd0e23d90d3fe upstream.

A bug in the family-model-stepping matching code caused the presence of
errata to go undetected when OSVW was not used. This causes hangs on
some K8 systems because the E400 workaround is not enabled.

Signed-off-by: Hans Rosenfeld <hans.rosenfeld@amd.com>
LKML-Reference: <1282141190-930137-1-git-send-email-hans.rosenfeld@amd.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>