[PATCH RESEND 6/6] clk: s5p-g2d: Fix incorrect usage of IS_ERR_OR_NULL

[Dan Carpenter]

Come on...  Don't say we haven't read comment.  Obviously, the first
thing we did was read that comment.  I've read it many times at this
point and I still think we should add in a bit which says:

"NOTE:  Drivers should treat the return value as an opaque cookie
and not dereference it.  NULL returns don't imply an error so don't
use IS_ERR_OR_NULL() to check for errors."

regards,
dan carpenter