Fix clang warning in croutine and stream buffer (#686)

* Fix document warning in croutine
* Fix cast-qual warning in stream buffer
diff --git a/include/croutine.h b/include/croutine.h
index 8ac4aa5..96e3972 100644
--- a/include/croutine.h
+++ b/include/croutine.h
@@ -53,11 +53,11 @@
 typedef struct corCoRoutineControlBlock
 {
     crCOROUTINE_CODE pxCoRoutineFunction;
-    ListItem_t xGenericListItem; /*< List item used to place the CRCB in ready and blocked queues. */
-    ListItem_t xEventListItem;   /*< List item used to place the CRCB in event lists. */
-    UBaseType_t uxPriority;      /*< The priority of the co-routine in relation to other co-routines. */
-    UBaseType_t uxIndex;         /*< Used to distinguish between co-routines when multiple co-routines use the same co-routine function. */
-    uint16_t uxState;            /*< Used internally by the co-routine implementation. */
+    ListItem_t xGenericListItem; /**< List item used to place the CRCB in ready and blocked queues. */
+    ListItem_t xEventListItem;   /**< List item used to place the CRCB in event lists. */
+    UBaseType_t uxPriority;      /**< The priority of the co-routine in relation to other co-routines. */
+    UBaseType_t uxIndex;         /**< Used to distinguish between co-routines when multiple co-routines use the same co-routine function. */
+    uint16_t uxState;            /**< Used internally by the co-routine implementation. */
 } CRCB_t;                        /* Co-routine control block.  Note must be identical in size down to uxPriority with TCB_t. */
 
 /**
diff --git a/stream_buffer.c b/stream_buffer.c
index 7754306..cbc0939 100644
--- a/stream_buffer.c
+++ b/stream_buffer.c
@@ -478,7 +478,7 @@
                                               StaticStreamBuffer_t ** ppxStaticStreamBuffer )
     {
         BaseType_t xReturn;
-        const StreamBuffer_t * const pxStreamBuffer = xStreamBuffer;
+        StreamBuffer_t * const pxStreamBuffer = xStreamBuffer;
 
         configASSERT( pxStreamBuffer );
         configASSERT( ppucStreamBufferStorageArea );