iwlwifi: declare static for iwl_sram_cleanup function

Signed-off-by: Wey-Yi Guy <wey-yi.w.guy@intel.com>
diff --git a/drivers/net/wireless/iwlwifi/iwl-sv-open.c b/drivers/net/wireless/iwlwifi/iwl-sv-open.c
index 4ea64d65..21b2fbb 100644
--- a/drivers/net/wireless/iwlwifi/iwl-sv-open.c
+++ b/drivers/net/wireless/iwlwifi/iwl-sv-open.c
@@ -184,7 +184,7 @@
 	priv->testmode_sram.sram_readed = false;
 }
 
-void iwl_sram_cleanup(struct iwl_priv *priv)
+static void iwl_sram_cleanup(struct iwl_priv *priv)
 {
 	if (priv->testmode_sram.sram_readed) {
 		kfree(priv->testmode_sram.buff_addr);