KVM: selftests: Increase UCALL_MAX_ARGS to 7

Increase UCALL_MAX_ARGS to 7 to allow GUEST_ASSERT_4 to pass 3 builtin
ucall arguments specified in guest_assert_builtin_args plus 4
user-specified arguments.
Signed-off-by: NColton Lewis <coltonlewis@google.com>
Reviewed-by: NAndrew Jones <drjones@redhat.com>
Link: https://lore.kernel.org/r/20220615193116.806312-3-coltonlewis@google.comSigned-off-by: NSean Christopherson <seanjc@google.com>

tools/testing/selftests/kvm/include/ucall_common.h

@@ -16,7 +16,7 @@ enum {
 	UCALL_UNHANDLED,
 };
 
-#define UCALL_MAX_ARGS 6
+#define UCALL_MAX_ARGS 7
 
 struct ucall {
 	uint64_t cmd;