scsi: megaraid: Remove set but unused variable

In mega_is_bios_enabled(), the variable ret is set but unused. Remove it to
avoid a compiler warning.

Link: https://lore.kernel.org/r/20200706123352.452003-1-damien.lemoal@wdc.comSigned-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/megaraid.c

@@ -3571,7 +3571,6 @@ mega_is_bios_enabled(adapter_t *adapter)
 {
 	unsigned char	raw_mbox[sizeof(struct mbox_out)];
 	mbox_t	*mbox;
-	int	ret;
 
 	mbox = (mbox_t *)raw_mbox;
 
@@ -3584,8 +3583,7 @@ mega_is_bios_enabled(adapter_t *adapter)
 	raw_mbox[0] = IS_BIOS_ENABLED;
 	raw_mbox[2] = GET_BIOS;
 
-
-	ret = issue_scb_block(adapter, raw_mbox);
+	issue_scb_block(adapter, raw_mbox);
 
 	return *(char *)adapter->mega_buffer;
 }