[SCSI] qla4xxx: Fix a Sparse warning message

Fix following message:-
drivers/scsi/qla4xxx/ql4_os.c:3266:5: error: symbol 'qla4xxx_post_aen_work' redeclared with different type (originally declared at drivers/scsi/qla4xxx/ql4_glbl.h:186) - incompatible argument 2 (different signedness)
Signed-off-by: Vikas Chaudhary <vikas.chaudhary@qlogic.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

drivers/scsi/qla4xxx/ql4_glbl.h

@@ -183,7 +183,8 @@ int qla4xxx_flash_ddb_change(struct scsi_qla_host *ha, uint32_t fw_ddb_index,
 int qla4xxx_ddb_change(struct scsi_qla_host *ha, uint32_t fw_ddb_index,
 		       struct ddb_entry *ddb_entry, uint32_t state);
 void qla4xxx_build_ddb_list(struct scsi_qla_host *ha, int is_reset);
-int qla4xxx_post_aen_work(struct scsi_qla_host *ha, uint32_t aen_code,
+int qla4xxx_post_aen_work(struct scsi_qla_host *ha,
+			  enum iscsi_host_event_code aen_code,
 			  uint32_t data_size, uint8_t *data);
 int qla4xxx_ping_iocb(struct scsi_qla_host *ha, uint32_t options,
 		      uint32_t payload_size, uint32_t pid, uint8_t *ipaddr);