Kernel: Fix correct argument order for userspace entry point

Author: https://github.com/gunnarbeutner
Commit: 90e3aa35ef
Pull-request: https://github.com/SerenityOS/serenity/pull/8317

Kernel/Syscalls/execve.cpp

@@ -144,8 +144,8 @@ static KResultOr<FlatPtr> make_userspace_context_for_main_thread([[maybe_unused]
     push_on_new_stack(argv);
     push_on_new_stack(argv_entries.size());
 #else
-    regs.rdi = argv;
-    regs.rsi = argv_entries.size();
+    regs.rdi = argv_entries.size();
+    regs.rsi = argv;
     regs.rdx = envp;
 #endif
     push_on_new_stack(0); // return address