sysprof: fix a message with stop without run

The function `misc.sysprof.stop()` reports that profiler is
already running:

| $ ./build/src/luajit -e 'print(misc.sysprof.stop())'
| nil     profiler is running already     22

The patch fixes that.

src/lj_sysprof.c

@@ -493,7 +493,7 @@ int lj_sysprof_stop(lua_State *L)
   global_State *g = sp->g;
   struct lj_wbuf *out = &sp->out;
 
-  if (SPS_IDLE == sp->state)
+  if (SPS_PROFILE != sp->state)
     return PROFILE_ERRRUN;
   else if (G(L) != g)
     return PROFILE_ERRUSE;

test/tarantool-tests/profilers/misclib-sysprof-lapi.test.lua

@@ -10,7 +10,7 @@ local test = tap.test("misc-sysprof-lapi"):skipcond({
   ["Disabled due to #10803"] = os.getenv("LUAJIT_TEST_USE_VALGRIND"),
 })
 
-test:plan(33)
+test:plan(34)
 
 jit.off()
 -- XXX: Run JIT tuning functions in a safe frame to avoid errors
@@ -98,7 +98,8 @@ assert(res, err)
 
 -- Not running.
 res, err, errno = misc.sysprof.stop()
-test:ok(res == nil and err, "res and error with not running")
+test:is(res, nil, "res with not running")
+test:ok(err:match("profiler is running already"), "error with not running")
 test:ok(type(errno) == "number", "errno with not running")
 
 -- Bad path.