Check for malloc failure in r2i_certpol.

See upstream's 34b9acbd3f.

Change-Id: I88d5b3cfbbe87e883323a9e6e1bf85227ed9576e
Reviewed-on: https://boringssl-review.googlesource.com/7811
Reviewed-by: Steven Valdez <svaldez@google.com>
Reviewed-by: David Benjamin <davidben@google.com>

crypto/x509v3/v3_cpols.c

@@ -190,6 +190,11 @@ static STACK_OF(POLICYINFO) *r2i_certpol(X509V3_EXT_METHOD *method,
                 goto err;
             }
             pol = POLICYINFO_new();
+            if (pol == NULL) {
+                OPENSSL_PUT_ERROR(X509V3, ERR_R_MALLOC_FAILURE);
+                ASN1_OBJECT_free(pobj);
+                goto err;
+            }
             pol->policyid = pobj;
         }
         if (!sk_POLICYINFO_push(pols, pol)) {