powerpc/5200: efika.c: Add of_node_put to avoid memory leak

This function is implemented as though the function of_get_next_child does
not increment the reference count of its result, but actually it does.
Thus the patch adds of_node_put in error handling code and drops a call to
of_node_get.

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

// <smpl>
@r exists@
local idexpression x;
expression E1;
position p1,p2;
@@

x@p1 = of_get_next_child(...);
... when != x = E1
of_node_get@p2(x)

@script:python@
p1 << r.p1;
p2 << r.p2;
@@

cocci.print_main("call",p1)
cocci.print_secs("get",p2)
// </smpl>

Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>