CLEANUP: tools: make resolve_sym_name() take a const pointer

When 0c439d895 ("BUILD: tools: make resolve_sym_name() return a const")
was written, the pointer argument ought to have been turned to const for
more flexibility. Let's do it now.
diff --git a/include/haproxy/tools.h b/include/haproxy/tools.h
index 651c070..76e6e73 100644
--- a/include/haproxy/tools.h
+++ b/include/haproxy/tools.h
@@ -990,7 +990,7 @@
 void dump_addr_and_bytes(struct buffer *buf, const char *pfx, const void *addr, int n);
 void dump_hex(struct buffer *out, const char *pfx, const void *buf, int len, int unsafe);
 int may_access(const void *ptr);
-const void *resolve_sym_name(struct buffer *buf, const char *pfx, void *addr);
+const void *resolve_sym_name(struct buffer *buf, const char *pfx, const void *addr);
 const char *get_exec_path();
 
 #if defined(USE_BACKTRACE)
diff --git a/src/tools.c b/src/tools.c
index 5895559..19b6122 100644
--- a/src/tools.c
+++ b/src/tools.c
@@ -4647,7 +4647,7 @@
  * The symbol's base address is returned, or NULL when unresolved, in order to
  * allow the caller to match it against known ones.
  */
-const void *resolve_sym_name(struct buffer *buf, const char *pfx, void *addr)
+const void *resolve_sym_name(struct buffer *buf, const char *pfx, const void *addr)
 {
 	const struct {
 		const void *func;