nvmem: fix nvmem_cell_read() return type doc

nvmem_cell_read() returns void *, not char *. This is a cleanup that got
left out of commit a6c50912508d ("nvmem: Declare nvmem_cell_read()
consistently").

Signed-off-by: Brian Norris <briannorris@chromium.org>
Fixes: a6c50912508d ("nvmem: Declare nvmem_cell_read() consistently")
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/nvmem/core.c

@@ -981,8 +981,8 @@ static int __nvmem_cell_read(struct nvmem_device *nvmem,
  * @cell: nvmem cell to be read.
  * @len: pointer to length of cell which will be populated on successful read.
  *
- * Return: ERR_PTR() on error or a valid pointer to a char * buffer on success.
- * The buffer should be freed by the consumer with a kfree().
+ * Return: ERR_PTR() on error or a valid pointer to a buffer on success. The
+ * buffer should be freed by the consumer with a kfree().
  */
 void *nvmem_cell_read(struct nvmem_cell *cell, size_t *len)
 {