perf util: Kill die() prototype, dead for a long time

[ Upstream commit e5cce1b ]

In fef2a73 ("perf tools: Kill die()") the die() function was
removed, but not the prototype in util.h, now when building with
LIBPERL=1, during a 'make -C tools/perf build-test' routine test, it is
failing as perl likes die() calls and then this clashes with this
remnant, remove it.

Fixes: fef2a73 ("perf tools: Kill die()")
Reviewed-by: Ian Rogers <irogers@google.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

Author: acmel

tools/perf/util/util.h

@@ -29,7 +29,6 @@ extern bool perf_guest;
 
 /* General helper functions */
 void usage(const char *err) __noreturn;
-void die(const char *err, ...) __noreturn __printf(1, 2);
 
 struct dirent;
 struct strlist;