perf symbols: Constify dso->long_name

Same reason as for dso->short_name, it may point to a const string, and
in most places it is treated as const, i.e. it is just accessed for
using its contents as a key or to show it on reports.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-nf7mxf33zt5qw207pbxxryot@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c
index 125cdc9..0bb830f 100644
--- a/tools/perf/util/header.c
+++ b/tools/perf/util/header.c
@@ -177,7 +177,7 @@
 			continue;		\
 		else
 
-static int write_buildid(char *name, size_t name_len, u8 *build_id,
+static int write_buildid(const char *name, size_t name_len, u8 *build_id,
 			 pid_t pid, u16 misc, int fd)
 {
 	int err;
@@ -209,7 +209,7 @@
 
 	dsos__for_each_with_build_id(pos, head) {
 		int err;
-		char  *name;
+		const char *name;
 		size_t name_len;
 
 		if (!pos->hit)
@@ -387,7 +387,7 @@
 {
 	bool is_kallsyms = dso->kernel && dso->long_name[0] != '/';
 	bool is_vdso = is_vdso_map(dso->short_name);
-	char *name = dso->long_name;
+	const char *name = dso->long_name;
 	char nm[PATH_MAX];
 
 	if (dso__is_kcore(dso)) {