fdtput.c: Fix memory leak.

CID 132821 (#1 of 1): Resource leak (RESOURCE_LEAK)
12. leaked_storage: Variable value going out of scope leaks the storage it points to.

Signed-off-by: Jean-Christophe Dubois <jcd@tribudubois.net>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>