tty: Move session_of_pgrp() and make static

tiocspgrp() is the lone caller of session_of_pgrp(); relocate and
limit to file scope.

Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Reviewed-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c
index 114854c..ae8f53c 100644
--- a/drivers/tty/tty_io.c
+++ b/drivers/tty/tty_io.c
@@ -2515,6 +2515,27 @@
 }
 EXPORT_SYMBOL_GPL(tty_get_pgrp);
 
+/*
+ * This checks not only the pgrp, but falls back on the pid if no
+ * satisfactory pgrp is found. I dunno - gdb doesn't work correctly
+ * without this...
+ *
+ * The caller must hold rcu lock or the tasklist lock.
+ */
+static struct pid *session_of_pgrp(struct pid *pgrp)
+{
+	struct task_struct *p;
+	struct pid *sid = NULL;
+
+	p = pid_task(pgrp, PIDTYPE_PGID);
+	if (p == NULL)
+		p = pid_task(pgrp, PIDTYPE_PID);
+	if (p != NULL)
+		sid = task_session(p);
+
+	return sid;
+}
+
 /**
  *	tiocgpgrp		-	get process group
  *	@tty: tty passed by user
diff --git a/include/linux/kernel.h b/include/linux/kernel.h
index 3d770f55..01bc530 100644
--- a/include/linux/kernel.h
+++ b/include/linux/kernel.h
@@ -411,9 +411,6 @@
 extern int kernel_text_address(unsigned long addr);
 extern int func_ptr_is_kernel_text(void *ptr);
 
-struct pid;
-extern struct pid *session_of_pgrp(struct pid *pgrp);
-
 unsigned long int_sqrt(unsigned long);
 
 extern void bust_spinlocks(int yes);
diff --git a/kernel/exit.c b/kernel/exit.c
index 5d30019..6a3e2e5 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -215,27 +215,6 @@
 }
 
 /*
- * This checks not only the pgrp, but falls back on the pid if no
- * satisfactory pgrp is found. I dunno - gdb doesn't work correctly
- * without this...
- *
- * The caller must hold rcu lock or the tasklist lock.
- */
-struct pid *session_of_pgrp(struct pid *pgrp)
-{
-	struct task_struct *p;
-	struct pid *sid = NULL;
-
-	p = pid_task(pgrp, PIDTYPE_PGID);
-	if (p == NULL)
-		p = pid_task(pgrp, PIDTYPE_PID);
-	if (p != NULL)
-		sid = task_session(p);
-
-	return sid;
-}
-
-/*
  * Determine if a process group is "orphaned", according to the POSIX
  * definition in 2.2.2.52.  Orphaned process groups are not to be affected
  * by terminal-generated stop signals.  Newly orphaned process groups are