staging: r8712u: Remove needless test for NULL

In commit ee6aeff, a swatch warning was fixed by moving some code inside
an if block that is executed only when the pointer padapter is not NULL.
In fact, padapter can never be NULL and the corect fix should have been
the removal of the test of padapter.

Reported-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>