selftests: kselftest framework: provide "finished" helper

Instead of having each time that wants to use ksft_exit() have to figure
out the internals of kselftest.h, add the helper ksft_finished() that
makes sure the passes, xfails, and skips are equal to the test plan count.

Link: https://lkml.kernel.org/r/[e-mail]
Signed-off-by: Kees Cook <[e-mail]>
Cc: Shuah Khan <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>
Signed-off-by: Linus Torvalds <[e-mail]>

tools/testing/selftests/kselftest.h

···
  *
  * When all tests are finished, clean up and exit the program with one of:
  *
+ *    ksft_finished();
  *    ksft_exit(condition);
  *    ksft_exit_pass();
  *    ksft_exit_fail();
···
 	else				\
 		ksft_exit_fail();	\
 	} while (0)
+
+/**
+ * ksft_finished() - Exit selftest with success if all tests passed
+ */
+#define ksft_finished()			\
+	ksft_exit(ksft_plan ==		\
+		  ksft_cnt.ksft_pass +	\
+		  ksft_cnt.ksft_xfail +	\
+		  ksft_cnt.ksft_xskip)
 
 static inline int ksft_exit_fail_msg(const char *msg, ...)
 {

tools/testing/selftests/vm/memfd_secret.c

···
 
 	close(fd);
 
-	ksft_exit(!ksft_get_fail_cnt());
+	ksft_finished();
 }
 
 #else /* __NR_memfd_secret */