runtime: Don't error out about SNP cert path on non SNP platforms

This error is specific to SNP platforms, so let's make sure we only
error this out when an SNP platform is used.

Signed-off-by: Fabiano Fidêncio <fabiano@fidencio.org>

src/runtime/pkg/katautils/config.go

@@ -299,6 +299,16 @@ func (h hypervisor) firmware() (string, error) {
 }
 
 func (h hypervisor) snpCertsPath() (string, error) {
+	// snpCertsPath only matter when using Confidential Guests
+	if !h.ConfidentialGuest {
+		return "", nil
+	}
+
+	// snpCertsPath only matter for SNP guests
+	if !h.SevSnpGuest {
+		return "", nil
+	}
+
 	p := h.SnpCertsPath
 
 	if p == "" {