selftests/clone3: ksft_exit functions do not return

selftests/clone3: ksft_exit functions do not return

After commit f7d5bcd35d42 ("selftests: kselftest: Mark functions that
unconditionally call exit() as __noreturn"), ksft_exit_...() functions
are marked as __noreturn, which means the return type should not be
'int' but 'void' because they are not returning anything (and never were
since exit() has always been called).

To facilitate updating the return type of these functions, remove
'return' before the calls to ksft_exit_{pass,fail}(), as __noreturn
prevents the compiler from warning that a caller of the ksft_exit
functions does not return a value because the program will terminate
upon calling these functions.

Just removing 'return' would have resulted in

  !ret ? ksft_exit_pass() : ksft_exit_fail();

so convert that into the more idiomatic

  if (ret)
    ksft_exit_fail();
  ksft_exit_pass();

Reviewed-by: Muhammad Usama Anjum <usama.anjum@collabora.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>