net: buf: Use void * instead of u8_t * for arbitrary data

This makes the net_buf_append_bytes() API consistent with all other
net_buf APIs that take a pointer to arbitrary data.

Fixes #9283

Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>

include/net/buf.h

@@ -1353,7 +1353,7 @@ typedef struct net_buf *(*net_buf_allocator_cb)(s32_t timeout, void *user_data);
  *         were no free fragments in a pool to accommodate all data.
  */
 u16_t net_buf_append_bytes(struct net_buf *buf, u16_t len,
-			   const u8_t *value, s32_t timeout,
+			   const void *value, s32_t timeout,
 			   net_buf_allocator_cb allocate_cb, void *user_data);
 
 /**

subsys/net/buf.c

@@ -722,7 +722,7 @@ int net_buf_linearize(void *dst, size_t dst_len, struct net_buf *src,
  * the buffer. It assumes that the buffer has at least one fragment.
  */
 u16_t net_buf_append_bytes(struct net_buf *buf, u16_t len,
-			   const u8_t *value, s32_t timeout,
+			   const void *value, s32_t timeout,
 			   net_buf_allocator_cb allocate_cb, void *user_data)
 {
 	struct net_buf *frag = net_buf_frag_last(buf);