Change docs according to review comments
diff --git a/include/mbedtls/x509_crt.h b/include/mbedtls/x509_crt.h
index 67a24f0..96f0142 100644
--- a/include/mbedtls/x509_crt.h
+++ b/include/mbedtls/x509_crt.h
@@ -532,15 +532,15 @@
*
* \param p_ctx An opaque context passed to the callback.
* \param child The certificate for which to search a potential signer.
- * This must point to a readable certificate.
+ * This will point to a readable certificate.
* \param candidate_cas The address at which to store the address of the first
* entry in the generated linked list of candidate signers.
- * This must not be \c NULL.
+ * This will not be \c NULL.
*
* \note The callback must only return a non-zero value on a
* fatal error. If, in contrast, the search for a potential
* signer completes without a single candidate, the
- * callback must return \c 0 and get \c *candidate_cas
+ * callback must return \c 0 and set \c *candidate_cas
* to \c NULL.
*
* \return \c 0 on success. In this case, \c *candidate_cas points