drivers/edac/cell_edac.c: Add missing of_node_put

of_node_put is needed before discarding a value received from of_find_node_by_name, eg in error handling code or when the device node is no longer used.

The semantic match that catches the bug is as follows:
(http://www.emn.fr/x-info/coccinelle/)

// <smpl>
@r exists@
local idexpression struct device_node *n;
position p1, p2;
statement S1,S2;
expression E,E1;
expression *ptr != NULL;
@@

(
if (!(n@p1 = of_find_node_by_name(...))) S1
|
n@p1 = of_find_node_by_name(...)
)
<... when != of_node_put(n)

    when != if (...) { <+... of_node_put(n) ...+> }
    when != true !n  || ...
    when != n = E
    when != E = n

if (!n || ...) S2
...>
(
return \(0\|<+...n...+>\|ptr\);
|
return@p2 ...;
|
n = E1
|
E1 = n
)
@script:python@
p1 << r.p1;
p2 << r.p2;
@@

print "* file: %s of_find_node_by_name %s return %s" % (p1[0].file,p1[0].line,p2[0].line) // </smpl>

---
 drivers/edac/cell_edac.c |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)

index cd2e3b8..cbc448b 100644
@@ -139,6 +139,7 @@ static void __devinit cell_edac_init_csrows(struct mem_ctl_info *mci)
 			continue;
 		if (of_node_to_nid(np) != priv->node)
 			continue;
+		of_node_put(np);
 		csrow->first_page = r.start >> PAGE_SHIFT;
 		csrow->nr_pages = (r.end - r.start + 1) >> PAGE_SHIFT;
 		csrow->last_page = csrow->first_page + csrow->nr_pages - 1;

Nicolas Palix