fix warning:unused variable 'count' & add return value

Signed-off-by: Nleijiawei <18691361562@163.com>

testsuites/unittest/extended/signal/full/signal_test_017.cpp

@@ -53,7 +53,7 @@ static void *ThreadSetFunc2(void *arg)
     retValue = sigwait(&set, &sig);
     ICUNIT_ASSERT_EQUAL_NULL(retValue, 0, retValue);
 
-	return NULL;
+    return NULL;
 }
 
 static void *ThreadSetDfl(void *arg)
@@ -72,7 +72,7 @@ static void *ThreadSetDfl(void *arg)
     retValue = sigwait(&set, &sig);
     ICUNIT_ASSERT_EQUAL_NULL(retValue, 0, retValue);
 
-	return NULL;
+    return NULL;
 }
 
 static void *ThreadKill(void *arg)
@@ -91,7 +91,7 @@ static void *ThreadKill(void *arg)
     retValue = sigwait(&set, &sig);
     ICUNIT_ASSERT_EQUAL_NULL(retValue, 0, retValue);
 
-	return NULL;
+    return NULL;
 }
 
 static int TestMultiPthreadFatherProcessExit()