no KERN_PROC_PATHNAME on OpenBSD

Index: vm/main.c
--- vm/main.c.orig
+++ vm/main.c
@@ -85,7 +85,6 @@ static char *executable_path() {
         int mib[4];
         mib[0] = CTL_KERN;
         mib[1] = KERN_PROC;
-        mib[2] = KERN_PROC_PATHNAME;
         mib[3] = -1;
 	static char path[MAXPATHLEN];
         size_t cb = sizeof(path);
