[PATCH] net: hwbm: if CONFIG_NET_HWBM unset, make stub functions static

["Ben Dooks (Codethink)" <ben.dooks@codethink.co.uk>]

If CONFIG_NET_HWBM is not set, then these stub functions in
<net/hwbm.h> should be declared static to avoid trying to
export them from any driver that includes this.

Note, add __maybe_unused as the marvell mvneta.c driver will
otherwise cause gcc warnings from these.

Fixes the following sparse warnings:

./include/net/hwbm.h:24:6: warning: symbol 'hwbm_buf_free' was not declared. Should it be static?
./include/net/hwbm.h:25:5: warning: symbol 'hwbm_pool_refill' was not declared. Should it be static?
./include/net/hwbm.h:26:5: warning: symbol 'hwbm_pool_add' was not declared. Should it be static?

Signed-off-by: Ben Dooks (Codethink) <ben.dooks@codethink.co.uk>
---
Cc: "David S. Miller" <davem@davemloft.net>
Cc: netdev@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
---
 include/net/hwbm.h | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/include/net/hwbm.h b/include/net/hwbm.h
index 81643cf8a1c4..cb5e6de8b7cd 100644
--- a/include/net/hwbm.h
+++ b/include/net/hwbm.h
@@ -21,9 +21,9 @@ void hwbm_buf_free(struct hwbm_pool *bm_pool, void *buf);
 int hwbm_pool_refill(struct hwbm_pool *bm_pool, gfp_t gfp);
 int hwbm_pool_add(struct hwbm_pool *bm_pool, unsigned int buf_num);
 #else
-void hwbm_buf_free(struct hwbm_pool *bm_pool, void *buf) {}
-int hwbm_pool_refill(struct hwbm_pool *bm_pool, gfp_t gfp) { return 0; }
-int hwbm_pool_add(struct hwbm_pool *bm_pool, unsigned int buf_num)
+static void __maybe_unused hwbm_buf_free(struct hwbm_pool *bm_pool, void *buf) {}
+static int __maybe_unused hwbm_pool_refill(struct hwbm_pool *bm_pool, gfp_t gfp) { return 0; }
+static int __maybe_unused hwbm_pool_add(struct hwbm_pool *bm_pool, unsigned int buf_num)
 { return 0; }
 #endif /* CONFIG_HWBM */
 #endif /* _HWBM_H */
-- 
2.23.0