Remove -fpic from CFLAGS
    
    The combination of -O2 and -fpic seems to be causing a very oddball bug
    in sparse's handling of err.h. expr->ctype->ctype.modifiers is ending
    up corrupt.
    
    I suspect this is sparse relying on some undefined behavior that is
    tricking the optimizer into not setting this field properly, but I've
    not yet been able to track down the root cause.
    
    For now, just remove -fpic as it shouldn't matter much for sparse
    anyway. Longer term, we can track the bug here to try and nail down
    what's going wrong.
    
        https://bugzilla.redhat.com/show_bug.cgi?id=1109560
    
    Signed-off-by: Jeff Layton <jlayton@primarydata.com>