staging: wilc1000: replace MALLOC_WILC_BUFFER() macro to avoid possible memory leak

The MALLOC_WILC_BUFFER() macro was using a return statement, and didn't
take care of possible memory leaks and subsequent bugs when it was failing
after succeeding some allocations. This patch corrects this behavior.
Signed-off-by: Raphaël Beamonte <raphael.beamonte@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/wilc1000/wilc_exported_buf.c

@@ -8,13 +8,6 @@
 #define LINUX_TX_SIZE	(64 * 1024)
 #define WILC1000_FW_SIZE (4 * 1024)
 
-#define MALLOC_WILC_BUFFER(name, size)	\
-	exported_ ## name = kmalloc(size, GFP_KERNEL);	  \
-	if (!exported_ ## name) {   \
-		printk("fail to alloc: %s memory\n", exported_ ## name);  \
-		return -ENOBUFS;	\
-	}
-
 /*
  * Add necessary buffer pointers
  */
@@ -46,11 +39,29 @@ static int __init wilc_module_init(void)
 	/*
 	 * alloc necessary memory
 	 */
-	MALLOC_WILC_BUFFER(g_tx_buf, LINUX_TX_SIZE)
-	MALLOC_WILC_BUFFER(g_rx_buf, LINUX_RX_SIZE)
-	MALLOC_WILC_BUFFER(g_fw_buf, WILC1000_FW_SIZE)
+	exported_g_tx_buf = kmalloc(LINUX_TX_SIZE, GFP_KERNEL);
+	if (!exported_g_tx_buf)
+		return -ENOMEM;
+
+	exported_g_rx_buf = kmalloc(LINUX_RX_SIZE, GFP_KERNEL);
+	if (!exported_g_rx_buf)
+		goto free_g_tx_buf;
+
+	exported_g_fw_buf = kmalloc(WILC1000_FW_SIZE, GFP_KERNEL);
+	if (!exported_g_fw_buf)
+		goto free_g_rx_buf;
 
 	return 0;
+
+free_g_rx_buf:
+	kfree(exported_g_rx_buf);
+	exported_g_rx_buf = NULL;
+
+free_g_tx_buf:
+	kfree(exported_g_tx_buf);
+	exported_g_tx_buf = NULL;
+
+	return -ENOMEM;
 }
 
 static void __exit wilc_module_deinit(void)