kernel.spec: Fix up mixed indents
    
    There are several instances of mixed spaces and tabs throughout the
    kernel.  This makes vim yell and rpmlint complain, so....
    
    It doesn't look like there was any consistency in the expected tab widths
    used, so I just tried to line things up as it appears to have been
    intended.
    
    [labbott: Tweaked commit text, fixed ever popular kenrel typo]