staging: rtl8188eu: core: rtw_recv.c: fix a paranthesis issue around pframe -> list in rtw_recv.c

Remove unnecessary parathesis issue around '->' .
Issue found by checkpatch.pl semantic patch results for
rtw_recv.c

CHECK: Remove unnecessary paranthesis around pframe -> list

Signed-off-by: Sanjana Sanikommu <sanjana99reddy99@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>