[PATCH] perf: Use (long) for iterator for bfd symbols

[Dmitry Safonov]

GCC (GCC) 8.4.0 20200304 fails to build perf with:
: util/symbol.c: In function 'dso__load_bfd_symbols':
: util/symbol.c:1626:16: error: comparison of integer expressions of different signednes
:   for (i = 0; i < symbols_count; ++i) {
:                 ^
: util/symbol.c:1632:16: error: comparison of integer expressions of different signednes
:    while (i + 1 < symbols_count &&
:                 ^
: util/symbol.c:1637:13: error: comparison of integer expressions of different signednes
:    if (i + 1 < symbols_count &&
:              ^
: cc1: all warnings being treated as errors

It's unlikely that the symtable will be that big, but the fix is
oneliner and as perf has CORE_CFLAGS += -Wextra, which makes build to
fail together with CORE_CFLAGS += -Werror

Fixes: eac9a4342e54 ("perf symbols: Try reading the symbol table with libbfd")
Cc: Alexander Shishkin <alexander.shishkin@xxxxxxxxxxxxxxx>
Cc: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Jacek Caban <jacek@xxxxxxxxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Mark Rutland <mark.rutland@xxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Remi Bernon <rbernon@xxxxxxxxxxxxxxx>
Signed-off-by: Dmitry Safonov <dima@xxxxxxxxxx>
---
 tools/perf/util/symbol.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c
index 64a039cbba1b..1645fb4ec9ed 100644
--- a/tools/perf/util/symbol.c
+++ b/tools/perf/util/symbol.c
@@ -1561,12 +1561,11 @@ static int bfd2elf_binding(asymbol *symbol)
 int dso__load_bfd_symbols(struct dso *dso, const char *debugfile)
 {
 	int err = -1;
-	long symbols_size, symbols_count;
+	long symbols_size, symbols_count, i;
 	asection *section;
 	asymbol **symbols, *sym;
 	struct symbol *symbol;
 	bfd *abfd;
-	u_int i;
 	u64 start, len;
 
 	abfd = bfd_openr(dso->long_name, NULL);
-- 
2.30.0