KVM: selftests: Convert the x86 userspace I/O test to printf guest assert

Convert x86's userspace I/O test to use printf-based guest asserts.

Link: https://lore.kernel.org/r/20230729003643.1053367-30-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>

Author: sean-jc

tools/testing/selftests/kvm/x86_64/userspace_io_test.c

@@ -1,4 +1,6 @@
 // SPDX-License-Identifier: GPL-2.0
+#define USE_GUEST_ASSERT_PRINTF 1
+
 #include <fcntl.h>
 #include <stdio.h>
 #include <stdlib.h>
@@ -20,8 +22,8 @@ static void guest_ins_port80(uint8_t *buffer, unsigned int count)
 		end = (unsigned long)buffer + 8192;
 
 	asm volatile("cld; rep; insb" : "+D"(buffer), "+c"(count) : "d"(0x80) : "memory");
-	GUEST_ASSERT_1(count == 0, count);
-	GUEST_ASSERT_2((unsigned long)buffer == end, buffer, end);
+	GUEST_ASSERT_EQ(count, 0);
+	GUEST_ASSERT_EQ((unsigned long)buffer, end);
 }
 
 static void guest_code(void)
@@ -43,7 +45,9 @@ static void guest_code(void)
 	memset(buffer, 0, sizeof(buffer));
 	guest_ins_port80(buffer, 8192);
 	for (i = 0; i < 8192; i++)
-		GUEST_ASSERT_2(buffer[i] == 0xaa, i, buffer[i]);
+		__GUEST_ASSERT(buffer[i] == 0xaa,
+			       "Expected '0xaa', got '0x%x' at buffer[%u]",
+			       buffer[i], i);
 
 	GUEST_DONE();
 }
@@ -91,7 +95,7 @@ int main(int argc, char *argv[])
 	case UCALL_DONE:
 		break;
 	case UCALL_ABORT:
-		REPORT_GUEST_ASSERT_2(uc, "argN+1 = 0x%lx, argN+2 = 0x%lx");
+		REPORT_GUEST_ASSERT(uc);
 	default:
 		TEST_FAIL("Unknown ucall %lu", uc.cmd);
 	}