Staging: rtl8192u: ieee80211: Fix if-else coding style issue

Fix following checkpatch.pl warning by adding braces around if
statement:
CHECK: braces {} should be used on all arms of this statement

Signed-off-by: Puranjay Mohan <puranjay12@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>