staging: lustre: osc: drop trivially useless initialization

Remove initialization of a variable that is immediately reassigned.

The semantic patch that makes this change is as follows:
(http://coccinelle.lip6.fr/)

// <smpl>
@@
type T;
identifier x;
constant C;
expression e;
@@

T x
- = C
 ;
x = e;
// </smpl>
Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/lustre/lustre/osc/osc_page.c

@@ -471,7 +471,7 @@ static int osc_page_flush(const struct lu_env *env,
 			  struct cl_io *io)
 {
 	struct osc_page *opg = cl2osc_page(slice);
-	int rc = 0;
+	int rc;
 
 	rc = osc_flush_async_page(env, io, opg);
 	return rc;