staging: android: ion: fix wrong init of dma_buf_export_info

Fixes: 817bd7253291 ("dma-buf: cleanup dma_buf_export() to make it
easily extensible")

Stupid copy-paste from me in the above patch leads to the following static
checker warning:

        drivers/staging/android/ion/ion.c:1112 ion_share_dma_buf()
        error: potentially dereferencing uninitialized 'buffer'.

drivers/staging/android/ion/ion.c
  1103  struct dma_buf *ion_share_dma_buf(struct ion_client *client,
  1104                                                  struct
ion_handle *handle)
  1105  {
  1106          struct ion_buffer *buffer;
                                   ^^^^^^
  1107          struct dma_buf *dmabuf;
  1108          bool valid_handle;
  1109          DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
  1110
  1111          exp_info.ops = &dma_buf_ops;
  1112          exp_info.size = buffer->size;
                                ^^^^^^
  1113          exp_info.flags = O_RDWR;
  1114          exp_info.priv = buffer;
                                ^^^^^^
And here also.

  1115

This patch corrects this stupidity.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org>