scsi: target/iscsi: fix possible condition with no effect (if == else)

Fix the following warning reported by coccicheck:

drivers/target/iscsi/iscsi_target_nego.c:175:6-8: WARNING: possible
condition with no effect (if == else)
Signed-off-by: Hariprasad Kelam <hariprasad.kelam@gmail.com>
Reviewed-by: David Disseldorp <ddiss@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/target/iscsi/iscsi_target_nego.c

@@ -160,22 +160,11 @@ static u32 iscsi_handle_authentication(
 
 	if (strstr("None", authtype))
 		return 1;
-#ifdef CANSRP
-	else if (strstr("SRP", authtype))
-		return srp_main_loop(conn, auth, in_buf, out_buf,
-				&in_length, out_length);
-#endif
 	else if (strstr("CHAP", authtype))
 		return chap_main_loop(conn, auth, in_buf, out_buf,
 				&in_length, out_length);
-	else if (strstr("SPKM1", authtype))
-		return 2;
-	else if (strstr("SPKM2", authtype))
-		return 2;
-	else if (strstr("KRB5", authtype))
-		return 2;
-	else
-		return 2;
+	/* SRP, SPKM1, SPKM2 and KRB5 are unsupported */
+	return 2;
 }
 
 static void iscsi_remove_failed_auth_entry(struct iscsi_conn *conn)