Fix comment typos (likely copy-and-paste errors)

Fix comment typos for aom_codec_destroy() and aom_codec_enc_init_ver().

Change-Id: I39edae835ed0752b569e8e7328d0709c59724ac2
diff --git a/aom/aom_codec.h b/aom/aom_codec.h
index 6a9fb7b..416c0c0 100644
--- a/aom/aom_codec.h
+++ b/aom/aom_codec.h
@@ -444,9 +444,11 @@
  * \param[in] ctx   Pointer to this instance's context
  *
  * \retval #AOM_CODEC_OK
- *     The codec algorithm initialized.
- * \retval #AOM_CODEC_MEM_ERROR
- *     Memory allocation failed.
+ *     The codec instance has been destroyed.
+ * \retval #AOM_CODEC_INVALID_PARAM
+ *     ctx is a null pointer.
+ * \retval #AOM_CODEC_ERROR
+ *     Codec context not initialized.
  */
 aom_codec_err_t aom_codec_destroy(aom_codec_ctx_t *ctx);
 
diff --git a/aom/aom_decoder.h b/aom/aom_decoder.h
index 5ce7c7b..f3f11d8 100644
--- a/aom/aom_decoder.h
+++ b/aom/aom_decoder.h
@@ -113,7 +113,7 @@
  * \param[in]    ver     ABI version number. Must be set to
  *                       AOM_DECODER_ABI_VERSION
  * \retval #AOM_CODEC_OK
- *     The decoder algorithm initialized.
+ *     The decoder algorithm has been initialized.
  * \retval #AOM_CODEC_MEM_ERROR
  *     Memory allocation failed.
  */
diff --git a/aom/aom_encoder.h b/aom/aom_encoder.h
index 87adb98..b4f7124 100644
--- a/aom/aom_encoder.h
+++ b/aom/aom_encoder.h
@@ -919,7 +919,7 @@
  * \param[in]    ver     ABI version number. Must be set to
  *                       AOM_ENCODER_ABI_VERSION
  * \retval #AOM_CODEC_OK
- *     The decoder algorithm initialized.
+ *     The encoder algorithm has been initialized.
  * \retval #AOM_CODEC_MEM_ERROR
  *     Memory allocation failed.
  */