i386/cpu: Use CPUID_MODEL_ID_SZ instead of hardcoded 48

There is already the MACRO CPUID_MODEL_ID_SZ defined in QEMU. Use it to
replace all the hardcoded 48.

Opportunistically fix the indentation of CPUID_VENDOR_SZ.

Signed-off-by: Xiaoyao Li <xiaoyao.li@intel.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Link: https://lore.kernel.org/r/20250630080610.3151956-2-xiaoyao.li@intel.com
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

target/i386/cpu.c

@@ -6469,11 +6469,11 @@ static char *x86_cpuid_get_model_id(Object *obj, Error **errp)
     char *value;
     int i;
 
-    value = g_malloc(48 + 1);
-    for (i = 0; i < 48; i++) {
+    value = g_malloc(CPUID_MODEL_ID_SZ + 1);
+    for (i = 0; i < CPUID_MODEL_ID_SZ; i++) {
         value[i] = env->cpuid_model[i >> 2] >> (8 * (i & 3));
     }
-    value[48] = '\0';
+    value[CPUID_MODEL_ID_SZ] = '\0';
     return value;
 }
 
@@ -6488,7 +6488,7 @@ static void x86_cpuid_set_model_id(Object *obj, const char *model_id,
         model_id = "";
     }
     len = strlen(model_id);
-    memset(env->cpuid_model, 0, 48);
+    memset(env->cpuid_model, 0, CPUID_MODEL_ID_SZ);
     for (i = 0; i < 48; i++) {
         if (i >= len) {
             c = '\0';

target/i386/cpu.h

@@ -1159,7 +1159,8 @@ uint64_t x86_cpu_get_supported_feature_word(X86CPU *cpu, FeatureWord w);
 /* PMM enabled */
 #define CPUID_C000_0001_EDX_PMM_EN             (1U << 13)
 
-#define CPUID_VENDOR_SZ      12
+#define CPUID_VENDOR_SZ     12
+#define CPUID_MODEL_ID_SZ   48
 
 #define CPUID_VENDOR_INTEL_1 0x756e6547 /* "Genu" */
 #define CPUID_VENDOR_INTEL_2 0x49656e69 /* "ineI" */

target/i386/host-cpu.c

@@ -80,7 +80,6 @@ bool host_cpu_realizefn(CPUState *cs, Error **errp)
     return true;
 }
 
-#define CPUID_MODEL_ID_SZ 48
 /**
  * cpu_x86_fill_model_id:
  * Get CPUID model ID string from host CPU.