hw-breakpoints: Fix broken hw-breakpoint sample module

The hw-breakpoint sample module has been broken during the
hw-breakpoint internals refactoring. Propagate the changes
to it.

Reported-by: "K. Prasad" <prasad@linux.vnet.ibm.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
diff --git a/kernel/hw_breakpoint.c b/kernel/hw_breakpoint.c
index e662dc9..9ea9414 100644
--- a/kernel/hw_breakpoint.c
+++ b/kernel/hw_breakpoint.c
@@ -454,6 +454,7 @@
 	/* return the error if any */
 	return ERR_PTR(err);
 }
+EXPORT_SYMBOL_GPL(register_wide_hw_breakpoint);
 
 /**
  * unregister_wide_hw_breakpoint - unregister a wide breakpoint in the kernel
@@ -470,7 +471,7 @@
 	}
 	free_percpu(cpu_events);
 }
-
+EXPORT_SYMBOL_GPL(unregister_wide_hw_breakpoint);
 
 static struct notifier_block hw_breakpoint_exceptions_nb = {
 	.notifier_call = hw_breakpoint_exceptions_notify,