greybus: Fix parameters of core_param()

core_param() takes four parameters instead of three and so results in this
compilation error:

greybus/core.c:25:33: error: macro "core_param" requires 4 arguments, but only 3 given
 core_param(nogreybus, bool, 0444);
                                 ^

Fix this by adding proper arguments to it.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>

drivers/staging/greybus/core.c

@@ -22,7 +22,7 @@ static bool nogreybus;
 #ifdef MODULE
 module_param(nogreybus, bool, 0444);
 #else
-core_param(nogreybus, bool, 0444);
+core_param(nogreybus, nogreybus, bool, 0444);
 #endif
 int greybus_disabled(void)
 {