Fix uninitialized variable in x509_crt

This patch fixes an issue we encountered with more stringent compiler
warnings.  The signature_is_good variable has a possibility of being
used uninitialized.  This patch moves the use of the variable to a
place where it cannot be used while uninitialized.

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

ChangeLog

@@ -56,6 +56,8 @@ Bugfix
      hang.
    * Clarify documentation of mbedtls_ssl_set_own_cert() regarding the absence
      of check for certificate/key matching. Reported by Attila Molnar, #507.
+   * Fix compiler warning in x509_crt.  Discovered and fixed by
+     Andy Gross (Linaro), #2392.
 
 = mbed TLS 2.14.1 branch released 2018-11-30
 

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;