added multiCondition sample

samples/multiCondition/bad.c

@@ -0,0 +1,11 @@
+static void f(bool b)
+{
+    if (b) {}
+    else if (!b) {}
+}
+
+int main()
+{
+    f(true);
+    return 0;
+}

samples/multiCondition/good.c

@@ -0,0 +1,11 @@
+static void f(bool b)
+{
+    if (b) {}
+    else {}
+}
+
+int main()
+{
+    f(true);
+    return 0;
+}

samples/multiCondition/out.txt

@@ -0,0 +1,9 @@
+samples\multiCondition\bad.c:4:14: style: Expression is always true because 'else if' condition is opposite to previous condition at line 3. [multiCondition]
+    else if (!b) {}
+             ^
+samples\multiCondition\bad.c:3:9: note: first condition
+    if (b) {}
+        ^
+samples\multiCondition\bad.c:4:14: note: else if condition is opposite to first condition
+    else if (!b) {}
+             ^