x86, microcode, AMD: Fix broken ucode patch size check
x86, microcode, AMD: Fix broken ucode patch size check

This issue was recently observed on an AMD C-50 CPU where a patch of
maximum size was applied.

Commit be62adb49294 ("x86, microcode, AMD: Simplify ucode verification")
added current_size in get_matching_microcode(). This is calculated as
size of the ucode patch + 8 (ie. size of the header). Later this is
compared against the maximum possible ucode patch size for a CPU family.
And of course this fails if the patch has already maximum size.

Cc: <4fbacc2fa0ffdbb11bf1ad6925b886ebd08dd15f@vger.kernel.org> [3.3+]
Signed-off-by: Andreas Herrmann <39e536ca8269572d74bff7f8e46f22412f1aee88@amd.com>
Signed-off-by: Borislav Petkov <2b4cb5acba6b5321acd37371d9b73a646c388783@amd.com>
Link: 0c4a29d94b4475ed95474e5bc2aaf417bcb1e6fd@amd64.org
Signed-off-by: H. Peter Anvin <8a453bad9912ffe59bc0f0b8abe03df9be19379e@linux.intel.com>

KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs