[PATCH -next] security: smack: add watch_queue.h header to fix build errors

[Randy Dunlap]

From: Randy Dunlap <rdunlap at infradead.org>

Fix build errors when CONFIG_WATCH_QUEUE=y by adding the
appropriate header file.

../security/smack/smack_lsm.c: In function ‘smack_post_notification’:
../security/smack/smack_lsm.c:4384:7: error: dereferencing pointer to incomplete type ‘struct watch_notification’
  if (n->type == WATCH_TYPE_META)
       ^~
../security/smack/smack_lsm.c:4384:17: error: ‘WATCH_TYPE_META’ undeclared (first use in this function); did you mean ‘TCA_PIE_BETA’?
  if (n->type == WATCH_TYPE_META)
                 ^~~~~~~~~~~~~~~
                 TCA_PIE_BETA

Signed-off-by: Randy Dunlap <rdunlap at infradead.org>
Cc: Casey Schaufler <casey at schaufler-ca.com>
Cc: David Howells <dhowells at redhat.com>
Cc: linux-security-module at vger.kernel.org
---
 security/smack/smack_lsm.c |    1 +
 1 file changed, 1 insertion(+)

--- linux-next-20191010.orig/security/smack/smack_lsm.c
+++ linux-next-20191010/security/smack/smack_lsm.c
@@ -42,6 +42,7 @@
 #include <linux/parser.h>
 #include <linux/fs_context.h>
 #include <linux/fs_parser.h>
+#include <linux/watch_queue.h>
 #include "smack.h"
 
 #define TRANS_TRUE	"TRUE"