staging: rtl8188eu: rtw_mlme_ext.c: simplify call to issue_action_BA()

Using the ternary operator allows to more concisely write the same
code, and to stay within 80 characters without even increasing the
number of lines.

Signed-off-by: Luca Ceresoli <luca@lucaceresoli.net>
Cc: Larry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>