staging: ion: fix spelling mistake in function name "detatch" -> "detach"

There is a spelling mistake in the function name ion_dma_buf_detatch.
Fix it by removing the extraneous t.

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Acked-by: Hridya Valsaraju <hridya@google.com>
Link: https://lore.kernel.org/r/20200805112655.17696-1-colin.king@canonical.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>