staging: wfx: rename wfx_tx_get_raw_link_id()

Since concept of "raw_link_id" does not exist anymore, rename
wfx_tx_get_raw_link_id() in wfx_tx_get_link_id().

Reviewed-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Jérôme Pouiller <jerome.pouiller@silabs.com>
Link: https://lore.kernel.org/r/20200401110405.80282-20-Jerome.Pouiller@silabs.com


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