target/i386/hvf: fix clang compilation warning

../target/i386/hvf/x86_cpuid.c:35:28: error: a function declaration without a prototype is deprecated in all versions of C

Fixes: 7cac7aa7040a823c585f1578a38f28e83c8bf3e1
Signed-off-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>
Link: https://lore.kernel.org/r/20241104222102.1522688-1-pierrick.bouvier@linaro.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
diff --git a/target/i386/hvf/x86_cpuid.c b/target/i386/hvf/x86_cpuid.c
index 3a11654..492e8bf 100644
--- a/target/i386/hvf/x86_cpuid.c
+++ b/target/i386/hvf/x86_cpuid.c
@@ -32,7 +32,7 @@
 static bool cached_xcr0;
 static uint64_t supported_xcr0;
 
-static void cache_host_xcr0()
+static void cache_host_xcr0(void)
 {
     if (cached_xcr0) {
         return;