arch/x86: Use RCU_INIT_POINTER(x, NULL) in kvm/vmx.c

Here rcu_assign_pointer() is ensuring that the
initialization of a structure is carried out before storing a pointer
to that structure.
So, rcu_assign_pointer(p, NULL) can always safely be converted to
RCU_INIT_POINTER(p, NULL).
Signed-off-by: NMonam Agarwal <monamagarwal123@gmail.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

arch/x86/kvm/vmx.c

@@ -9097,7 +9097,7 @@ static void __exit vmx_exit(void)
 	free_page((unsigned long)vmx_vmread_bitmap);
 
 #ifdef CONFIG_KEXEC
-	rcu_assign_pointer(crash_vmclear_loaded_vmcss, NULL);
+	RCU_INIT_POINTER(crash_vmclear_loaded_vmcss, NULL);
 	synchronize_rcu();
 #endif