yysyntax_error: prepare for readability of next patches.

yysyntax_error: prepare for readability of next patches.

These are purely whitespace changes that result in ugly code
but that make the next couple of patches much easier to read.
* data/glr.c (yyreportSyntaxError): Reindent.
* data/lalr1.cc (yy::parser::yysyntax_error_): Reindent.
* data/lalr1.java (YYParser::yysyntax_error): Reindent.
* data/yacc.c (yysyntax_error): Reindent.