greybus: endo: Fix compilation warning

WARNING: /home/viresh/work/repos/ara/greybus/greybus.o(.init.text+0xb8):
Section mismatch in reference from the function init_module() to the
function .exit.text:gb_endo_exit()

The function __init init_module() references
a function __exit gb_endo_exit().

Fix it by removing __exit from endo_exit().

Fixes: cf64356c5151 ("endo: define endo_init() and endo_exit()")
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

drivers/staging/greybus/endo.c

@@ -529,6 +529,6 @@ int __init gb_endo_init(void)
 	return 0;
 }
 
-void __exit gb_endo_exit(void)
+void gb_endo_exit(void)
 {
 }

drivers/staging/greybus/endo.h

@@ -50,7 +50,7 @@ struct gb_endo {
 struct greybus_host_device;
 
 int gb_endo_init(void) __init;
-void gb_endo_exit(void) __exit;
+void gb_endo_exit(void);
 
 struct gb_endo *gb_endo_create(struct greybus_host_device *hd,
 				u16 endo_id, u8 ap_intf_id);