ext: crypto: mbedtls: Fix uninitialized variable

This patch fixes an issue with an uninitialized variable in the x509
mbedtls feature.  I sent a related patch to the mbedtls project so
that this can be fixed in the future.

Mbed-TLS/mbedtls#2392

Signed-off-by: Andy Gross <andy.gross@linaro.org>

ext/lib/crypto/mbedtls/library/x509_crt.c

@@ -2088,15 +2088,13 @@ static int x509_crt_find_parent_in(
             continue;
         }
 
-        break;
-    }
-
-    if( parent != NULL )
-    {
         *r_parent = parent;
         *r_signature_is_good = signature_is_good;
+
+        break;
     }
-    else
+
+    if (parent == NULL)
     {
         *r_parent = fallback_parent;
         *r_signature_is_good = fallback_signature_is_good;