Harmonize lexer adjacent function parameter names.

Make sure that function declarations use names that exactly match the
corresponding names from function definitions for several "lexer
adjacent" backend functions.

These functions were missed by recent commits because they were obscured
by clang-tidy warnings about functions whose signature is directly under
the control of the lexer (flex seems to always generate function
declarations with unnamed parameters).  We probably can't fix most of
the warnings it generates for translation units that get built from .l
and .y files, but we can at least do this much.

Author: Peter Geoghegan <pg@bowt.ie>
Discussion: https://postgr.es/m/CAH2-WznJt9CMM9KJTMjJh_zbL5hD9oX44qdJ4aqZtjFi-zA3Tg@mail.gmail.com

src/bin/pgbench/exprparse.y

@@ -23,7 +23,7 @@
 
 PgBenchExpr *expr_parse_result;
 
-static PgBenchExprList *make_elist(PgBenchExpr *exp, PgBenchExprList *list);
+static PgBenchExprList *make_elist(PgBenchExpr *expr, PgBenchExprList *list);
 static PgBenchExpr *make_null_constant(void);
 static PgBenchExpr *make_boolean_constant(bool bval);
 static PgBenchExpr *make_integer_constant(int64 ival);

src/include/replication/syncrep.h

@@ -103,7 +103,7 @@ extern void SyncRepUpdateSyncStandbysDefined(void);
 extern int	syncrep_yyparse(void);
 extern int	syncrep_yylex(void);
 extern void syncrep_yyerror(const char *str);
-extern void syncrep_scanner_init(const char *query_string);
+extern void syncrep_scanner_init(const char *str);
 extern void syncrep_scanner_finish(void);
 
 #endif							/* _SYNCREP_H */

src/include/replication/walsender_private.h

@@ -119,7 +119,7 @@ extern void WalSndSetState(WalSndState state);
 extern int	replication_yyparse(void);
 extern int	replication_yylex(void);
 extern void replication_yyerror(const char *str) pg_attribute_noreturn();
-extern void replication_scanner_init(const char *query_string);
+extern void replication_scanner_init(const char *str);
 extern void replication_scanner_finish(void);
 extern bool replication_scanner_is_replication_command(void);