tools/resolve_btfids: Fix warnings

* make eprintf static, used only in main.c
* initialize ret in eprintf
* remove unused *tmp

v3:
* remove another err (Song Liu)

v2:
* remove unused 'int err = -1'

Signed-off-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20210329223143.3659983-1-sdf@google.com

Author: fomichev

tools/bpf/resolve_btfids/main.c

@@ -115,10 +115,10 @@ struct object {
 
 static int verbose;
 
-int eprintf(int level, int var, const char *fmt, ...)
+static int eprintf(int level, int var, const char *fmt, ...)
 {
 	va_list args;
-	int ret;
+	int ret = 0;
 
 	if (var >= level) {
 		va_start(args, fmt);
@@ -385,7 +385,7 @@ static int elf_collect(struct object *obj)
 static int symbols_collect(struct object *obj)
 {
 	Elf_Scn *scn = NULL;
-	int n, i, err = 0;
+	int n, i;
 	GElf_Shdr sh;
 	char *name;
 
@@ -402,11 +402,10 @@ static int symbols_collect(struct object *obj)
 	 * Scan symbols and look for the ones starting with
 	 * __BTF_ID__* over .BTF_ids section.
 	 */
-	for (i = 0; !err && i < n; i++) {
-		char *tmp, *prefix;
+	for (i = 0; i < n; i++) {
+		char *prefix;
 		struct btf_id *id;
 		GElf_Sym sym;
-		int err = -1;
 
 		if (!gelf_getsym(obj->efile.symbols, i, &sym))
 			return -1;