fixed readability-else-after-return clang-tidy warnings

Author: firewave

lib/checkbufferoverrun.cpp

@@ -603,7 +603,8 @@ static bool checkBufferSize(const Token *ftok, const Library::ArgumentChecks::Mi
     case Library::ArgumentChecks::MinSize::Type::STRLEN:
         if (settings.library.isargformatstr(ftok, minsize.arg)) {
             return getMinFormatStringOutputLength(args, minsize.arg) < bufferSize;
-        } else if (arg) {
+        }
+        if (arg) {
             const Token *strtoken = arg->getValueTokenMaxStrLength();
             if (strtoken)
                 return Token::getStrLength(strtoken) < bufferSize;

lib/mathlib.cpp

@@ -655,8 +655,7 @@ bool MathLib::isDecimalFloat(const std::string &str)
         case State::MANTISSA_PLUSMINUS:
             if (!std::isdigit(static_cast<unsigned char>(*it)))
                 return false;
-            else
-                state = State::MANTISSA_DIGITS;
+            state = State::MANTISSA_DIGITS;
             break;
         case State::MANTISSA_DIGITS:
             if (*it=='f' || *it=='F')