misc: ti-st: remove ptr from recv functions

misc: ti-st: remove ptr from recv functions

ptr is the same as data, so use ptr directly as a parameter and drop the
useless local variable.

Likely, the two were introduced to have a different type. But 'char' and
'unsigned char' are the same in the kernel for a long time.

Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/r/20230731080244.2698-10-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>