STAGING: Declare request_cache as static for drivers/staging/lustre/lustre/ptlrpc/client.c

Declare request_cache variable as static. It is only used by
drivers/staging/lustre/lustre/ptlrpc/client.c, and its naming is common
which will lead to namespace pollution.
Signed-off-by: Simon Guo <wei.guo.simon@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/lustre/lustre/ptlrpc/client.c

@@ -390,7 +390,7 @@ static int ptlrpc_at_recv_early_reply(struct ptlrpc_request *req)
 	return rc;
 }
 
-struct kmem_cache *request_cache;
+static struct kmem_cache *request_cache;
 
 int ptlrpc_request_cache_init(void)
 {