powerpc/maple: Add of_node_put to avoid memory leak

Add a call to of_node_put in the error handling code following a call to
of_find_node_by_path.

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

// <smpl>
@r exists@
local idexpression x;
expression E,E1;
statement S;
@@

*x =
(of_find_node_by_path
|of_find_node_by_name
|of_find_node_by_phandle
|of_get_parent
|of_get_next_parent
|of_get_next_child
|of_find_compatible_node
|of_match_node
)(...);
...
if (x == NULL) S
<... when != x = E
*if (...) {
  ... when != of_node_put(x)
      when != if (...) { ... of_node_put(x); ... }
(
  return <+...x...+>;
|
*  return ...;
)
}
...>
of_node_put(x);
// </smpl>

Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

arch/powerpc/platforms/maple/setup.c

@@ -358,6 +358,7 @@ static int __init maple_cpc925_edac_setup(void)
 	model = (const unsigned char *)of_get_property(np, "model", NULL);
 	if (!model) {
 		printk(KERN_ERR "%s: Unabel to get model info\n", __func__);
+		of_node_put(np);
 		return -ENODEV;
 	}