staging: rtl8188eu: core: rtw_xmit: Move constant of the right side

Constants should be on the right side of comparisons.

Issue found by checkpatch.pl script.

Signed-off-by: Georgiana Rodica Chelu <georgiana.chelu93@gmail.com>
Acked-by: Julia Lawall <julia.lawall@lip6.fr>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>