Fix test-cp-name-parser build, parser_fprintf undefined

Fix test-cp-name-parser build, parser_fprintf undefined

  $ make test-cp-name-parser
  ...
  test-cp-name-parser.o: In function `yy_symbol_print(_IO_FILE*, int, YYSTYPE const*, cpname_state*)':
  build/gdb/cp-name-parser.c.tmp:1335: undefined reference to `parser_fprintf(_IO_FILE*, char const*, ...)'
  build/gdb/cp-name-parser.c.tmp:1339: undefined reference to `parser_fprintf(_IO_FILE*, char const*, ...)'
  test-cp-name-parser.o: In function `yy_stack_print(short*, short*)':
  build/gdb/cp-name-parser.c.tmp:1350: undefined reference to `parser_fprintf(_IO_FILE*, char const*, ...)'
  build/gdb/cp-name-parser.c.tmp:1354: undefined reference to `parser_fprintf(_IO_FILE*, char const*, ...)'
  build/gdb/cp-name-parser.c.tmp:1356: undefined reference to `parser_fprintf(_IO_FILE*, char const*, ...)'
  build/gdb/cp-name-parser.c.tmp:1376: more undefined references to `parser_fprintf(_IO_FILE*, char const*, ...)' follow
  collect2: error: ld returned 1 exit status
  make: *** [Makefile:1833: test-cp-name-parser] Error 1

gdb/ChangeLog:
2019-03-12  Pedro Alves  <palves@redhat.com>

	* yy-remap.h [TEST_CPNAMES] (YYFPRINTF): Don't define.