crypto: sha1-ssse3 - Disable avx2

It has been reported that sha1-avx2 can cause page faults by reading
beyond the end of the input.  This patch disables it until it can be
fixed.

Cc: <stable@vger.kernel.org>
Fixes: 7c1da8d ("crypto: sha - SHA1 transform x86_64 AVX2")
Reported-by: Jan Stancek <jstancek@redhat.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

arch/x86/crypto/sha1_ssse3_glue.c

@@ -201,7 +201,7 @@ asmlinkage void sha1_transform_avx2(u32 *digest, const char *data,
 
 static bool avx2_usable(void)
 {
-	if (avx_usable() && boot_cpu_has(X86_FEATURE_AVX2)
+	if (false && avx_usable() && boot_cpu_has(X86_FEATURE_AVX2)
 		&& boot_cpu_has(X86_FEATURE_BMI1)
 		&& boot_cpu_has(X86_FEATURE_BMI2))
 		return true;