perf tools: Use %define api.pure full instead of %pure-parser

bison deprecated the "%pure-parser" directive in favor of "%define
api.pure full".

The api.pure got introduced in bison 2.3 (Oct 2007), so it seems safe to
use it without any version check.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Clark Williams <williams@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lore.kernel.org/lkml/20200112192259.GA35080@kravaSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/util/expr.y

@@ -12,7 +12,8 @@
 #define MAXIDLEN 256
 %}
 
-%pure-parser
+%define api.pure full
+
 %parse-param { double *final_val }
 %parse-param { struct parse_ctx *ctx }
 %parse-param { const char **pp }

tools/perf/util/parse-events.y

-%pure-parser
+%define api.pure full
 %parse-param {void *_parse_state}
 %parse-param {void *scanner}
 %lex-param {void* scanner}