trim fs/internal.h

some stuff in there can actually become static; some belongs to pnode.h
as it's a private interface between namespace.c and pnode.c...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

fs/exec.c

@@ -1225,7 +1225,7 @@ EXPORT_SYMBOL(install_exec_creds);
  * - the caller must hold ->cred_guard_mutex to protect against
  *   PTRACE_ATTACH
  */
-int check_unsafe_exec(struct linux_binprm *bprm)
+static int check_unsafe_exec(struct linux_binprm *bprm)
 {
 	struct task_struct *p = current, *t;
 	unsigned n_fs;