scsi: megaraid: Remove redundant assignment to variable 'retval'

The variable 'retval' is being assigned a value that is not being read
afterwards. The assignment is redundant and can be removed.

Cleans up clang scan warning:

Although the value stored to 'retval' is used in the enclosing
expression, the value is never actually read from 'retval'
[deadcode.DeadStores]
Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
Link: https://lore.kernel.org/r/20240118121441.2533620-1-colin.i.king@gmail.comSigned-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/megaraid.c

@@ -219,7 +219,7 @@ mega_query_adapter(adapter_t *adapter)
 	raw_mbox[3] = ENQ3_GET_SOLICITED_FULL;	/* i.e. 0x02 */
 
 	/* Issue a blocking command to the card */
-	if ((retval = issue_scb_block(adapter, raw_mbox))) {
+	if (issue_scb_block(adapter, raw_mbox)) {
 		/* the adapter does not support 40ld */
 
 		mraid_ext_inquiry	*ext_inq;