Fix error reporting in reindexdb

When failing to reindex a table or an index, reindexdb would generate an
extra error message related to a database failure, which is misleading.

Backpatch all the way down, as this has been introduced by 85e9a5a0.

Discussion: https://postgr.es/m/CAOBaU_Yo61RwNO3cW6WVYWwH7EYMPuexhKqufb2nFGOdunbcHw@mail.gmail.com
Author: Julien Rouhaud
Reviewed-by: Daniel Gustafsson, Álvaro Herrera, Tom Lane, Michael
Paquier
Backpatch-through: 9.4

src/bin/scripts/reindexdb.c

@@ -325,10 +325,10 @@ reindex_one_database(const char *name, const char *dbname, const char *type,
 		if (strcmp(type, "TABLE") == 0)
 			pg_log_error("reindexing of table \"%s\" in database \"%s\" failed: %s",
 						 name, PQdb(conn), PQerrorMessage(conn));
-		if (strcmp(type, "INDEX") == 0)
+		else if (strcmp(type, "INDEX") == 0)
 			pg_log_error("reindexing of index \"%s\" in database \"%s\" failed: %s",
 						 name, PQdb(conn), PQerrorMessage(conn));
-		if (strcmp(type, "SCHEMA") == 0)
+		else if (strcmp(type, "SCHEMA") == 0)
 			pg_log_error("reindexing of schema \"%s\" in database \"%s\" failed: %s",
 						 name, PQdb(conn), PQerrorMessage(conn));
 		else