keys: add missing include file for trusted and encrypted keys

This patch fixes the linux-next powerpc build errors as reported by
Stephen Rothwell.
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Mimi Zohar <zohar@us.ibm.com>
Tested-by: Rajiv Andrade <srajiv@linux.vnet.ibm.com>
Signed-off-by: James Morris <jmorris@namei.org>

security/keys/encrypted_defined.c

@@ -17,6 +17,7 @@
 #include <linux/slab.h>
 #include <linux/parser.h>
 #include <linux/string.h>
+#include <linux/err.h>
 #include <keys/user-type.h>
 #include <keys/trusted-type.h>
 #include <keys/encrypted-type.h>

security/keys/trusted_defined.c

@@ -17,6 +17,7 @@
 #include <linux/slab.h>
 #include <linux/parser.h>
 #include <linux/string.h>
+#include <linux/err.h>
 #include <keys/user-type.h>
 #include <keys/trusted-type.h>
 #include <linux/key-type.h>