scsi: megaraid_sas: remove set but not used variable 'sge_sz'

Fixes gcc '-Wunused-but-set-variable' warning:

drivers/scsi/megaraid/megaraid_sas_base.c: In function megasas_create_frame_pool:
drivers/scsi/megaraid/megaraid_sas_base.c:4124:6: warning: variable sge_sz set but not used [-Wunused-but-set-variable]

It's not used any more since commit 200aed58 ("megaraid_sas: endianness
related bug fixes and code optimization")
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Acked-by: Sumit Saxena <sumit.saxena@broadcom.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/megaraid/megaraid_sas_base.c

@@ -4122,22 +4122,11 @@ static int megasas_create_frame_pool(struct megasas_instance *instance)
 {
 	int i;
 	u16 max_cmd;
-	u32 sge_sz;
 	u32 frame_count;
 	struct megasas_cmd *cmd;
 
 	max_cmd = instance->max_mfi_cmds;
 
-	/*
-	 * Size of our frame is 64 bytes for MFI frame, followed by max SG
-	 * elements and finally SCSI_SENSE_BUFFERSIZE bytes for sense buffer
-	 */
-	sge_sz = (IS_DMA64) ? sizeof(struct megasas_sge64) :
-	    sizeof(struct megasas_sge32);
-
-	if (instance->flag_ieee)
-		sge_sz = sizeof(struct megasas_sge_skinny);
-
 	/*
 	 * For MFI controllers.
 	 * max_num_sge = 60