hv: use int32_t replace int

Since it's typedef in "include/lib/types.h"

Tracked-On: #861
Signed-off-by: Li, Fei1 <fei1.li@intel.com>

hypervisor/arch/x86/guest/ucode.c

@@ -37,7 +37,7 @@ void acrn_update_ucode(struct acrn_vcpu *vcpu, uint64_t v)
 	uint64_t gva, fault_addr;
 	struct ucode_header uhdr;
 	size_t data_size;
-	int err;
+	int32_t err;
 	uint32_t err_code;
 
 	spinlock_obtain(&micro_code_lock);