libbpf: Remove unnecessary usdt_rel_ip assignments

Coverity detected that usdt_rel_ip is unconditionally overwritten
anyways, so there is no need to unnecessarily initialize it with unused
value. Clean this up.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Yonghong Song <yhs@fb.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/bpf/20220705224818.4026623-4-andrii@kernel.org

tools/lib/bpf/usdt.c

@@ -652,11 +652,9 @@ static int collect_usdt_targets(struct usdt_manager *man, Elf *elf, const char *
 		 *
 		 *   [0] https://sourceware.org/systemtap/wiki/UserSpaceProbeImplementation
 		 */
-		usdt_rel_ip = usdt_abs_ip = note.loc_addr;
-		if (base_addr) {
+		usdt_abs_ip = note.loc_addr;
+		if (base_addr)
 			usdt_abs_ip += base_addr - note.base_addr;
-			usdt_rel_ip += base_addr - note.base_addr;
-		}
 
 		/* When attaching uprobes (which is what USDTs basically are)
 		 * kernel expects file offset to be specified, not a relative