Staging: rtl8188eu: core: rtw_xmit.c: Remove NULL test before vfree

The function vfree tests whether the argument is NULL and returns
immediately. So NULL test is not needed before vfree. Also remove blank
line between function calls.

Signed-off-by: Bhumika Goyal <bhumirks@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>