kselftest: Add mechanism for reporting a KSFT_ result code

Currently there's no helper which a test can use to report it's result as
a KSFT_ result code, we can report a boolean pass/fail but not a skip. This
is sometimes a useful idiom so let's add a helper ksft_test_result_report()
which translates into the relevant report types.

Due to the use of va_args in the result reporting functions this is done as
a macro rather than an inline function as one might expect, none of the
alternatives looked particularly great.

Resolved merge conflict in next betwwen the following commits:
f7d5bcd3 ("selftests: kselftest: Mark functions that unconditionally call exit() as __noreturn")

5d3a9274f0d1 ("kselftest: Add mechanism for reporting a KSFT_ result code")
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Shuah Khan <skhan@linuxfoundation.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

tools/testing/selftests/kselftest.h

@@ -20,6 +20,7 @@
  * and finally report the pass/fail/skip/xfail state of the test with one of:
  *
  *     ksft_test_result(condition, fmt, ...);
+ *     ksft_test_result_report(result, fmt, ...);
  *     ksft_test_result_pass(fmt, ...);
  *     ksft_test_result_fail(fmt, ...);
  *     ksft_test_result_skip(fmt, ...);
@@ -305,6 +306,27 @@ void ksft_test_result_code(int exit_code, const char *test_name,
 	printf("\n");
 }
 
+/**
+ * ksft_test_result() - Report test success based on truth of condition
+ *
+ * @condition: if true, report test success, otherwise failure.
+ */
+#define ksft_test_result_report(result, fmt, ...) do {		\
+	switch (result) {					\
+	case KSFT_PASS:						\
+		ksft_test_result_pass(fmt, ##__VA_ARGS__);	\
+		break;						\
+	case KSFT_FAIL:						\
+		ksft_test_result_fail(fmt, ##__VA_ARGS__);	\
+		break;						\
+	case KSFT_XFAIL:					\
+		ksft_test_result_xfail(fmt, ##__VA_ARGS__);	\
+		break;						\
+	case KSFT_SKIP:						\
+		ksft_test_result_skip(fmt, ##__VA_ARGS__);	\
+		break;						\
+	} } while (0)
+
 static inline __noreturn int ksft_exit_pass(void)
 {
 	ksft_print_cnts();