scsi: 3w-9xxx: Use flexible array members to avoid struct padding

In preparation for removing the "#pragma pack(1)" from the driver, fix all
instances where a trailing array member could be replaced by a flexible
array member. Since a flexible array member has zero size, it introduces no
padding, whether or not the struct is packed.

Link: https://lore.kernel.org/r/20210427235915.39211-2-samuel@sholland.org
Signed-off-by: Samuel Holland <samuel@sholland.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
diff --git a/drivers/scsi/3w-9xxx.h b/drivers/scsi/3w-9xxx.h
index 30109ae..23b312a 100644
--- a/drivers/scsi/3w-9xxx.h
+++ b/drivers/scsi/3w-9xxx.h
@@ -602,7 +602,7 @@ typedef struct TAG_TW_Ioctl_Apache {
 	TW_Ioctl_Driver_Command driver_command;
 	char padding[488];
 	TW_Command_Full firmware_command;
-	char data_buffer[1];
+	char data_buffer[];
 } TW_Ioctl_Buf_Apache;
 
 /* Lock structure for ioctl get/release lock */
@@ -618,7 +618,7 @@ typedef struct {
 	unsigned short	parameter_id;
 	unsigned short	parameter_size_bytes;
 	unsigned short  actual_parameter_size_bytes;
-	unsigned char	data[1];
+	unsigned char	data[];
 } TW_Param_Apache, *PTW_Param_Apache;
 
 /* Response queue */