staging: msm/lcdc.c: Convert IS_ERR result to PTR_ERR

This code elsewhere returns a negative constant to an indicate an error,
while IS_ERR returns the result of a >= operation.

The semantic patch that fixes this problem is as follows:
(http://coccinelle.lip6.fr/)

// <smpl>
@@
expression x;
@@

 if (...) { ...
- return IS_ERR(x);
+ return PTR_ERR(x);
}
// </smpl>

Signed-off-by: Julia Lawall <julia@diku.dk>
Acked-by: David Brown <davidb@codeaurora.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>