remoteproc: Fix a memory leak in an error handling path in 'rproc_handle_vdev()'

If 'copy_dma_range_map() fails, the memory allocated for 'rvdev' will leak.
Move the 'copy_dma_range_map()' call after the device registration so
that 'rproc_rvdev_release()' can be called to free some resources.

Also, branch to the error handling path if 'copy_dma_range_map()' instead
of a direct return to avoid some other leaks.

Fixes: e0d07278

 ("dma-mapping: introduce DMA range map, supplanting dma_pfn_offset")
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Reviewed-by: Jim Quinlan <james.quinlan@broadcom.com>
Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/e6d0dad6620da4fdf847faa903f79b735d35f262.1630755377.git.christophe.jaillet@wanadoo.fr