Add a note for OpenBSD and getting path names of running executables.

src/openrct2/platform/linux.c

@@ -57,6 +57,8 @@ void platform_get_exe_path(utf8 *outPath, size_t outSize)
 
     }
 #elif defined(__OpenBSD__)
+    // There is no way to get the path name of a running executable.
+    // If you are not using the port or package, you must change this line!
     strlcpy(exePath, "/usr/local/bin/", sizeof(exePath));
 #else
 #error "Platform does not support full path exe retrieval"