Fix assertion condition per review comment

Author: ldionne

libcxx/include/span

@@ -267,7 +267,7 @@ public:
   _LIBCPP_HIDE_FROM_ABI constexpr explicit span(_It __first, size_type __count) : __data_{std::to_address(__first)} {
     (void)__count;
     _LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(_Extent == __count, "size mismatch in span's constructor (iterator, len)");
-    _LIBCPP_ASSERT_VALID_INPUT_RANGE(__count == 0 ? true : std::to_address(__first) != nullptr,
+    _LIBCPP_ASSERT_VALID_INPUT_RANGE(__count == 0 || std::to_address(__first) != nullptr,
                                      "passed nullptr with non-zero length in span's constructor (iterator, len)");
   }
 
@@ -444,7 +444,7 @@ public:
   template <__span_compatible_iterator<element_type> _It>
   _LIBCPP_HIDE_FROM_ABI constexpr span(_It __first, size_type __count)
       : __data_{std::to_address(__first)}, __size_{__count} {
-    _LIBCPP_ASSERT_VALID_INPUT_RANGE(__count == 0 ? true : std::to_address(__first) != nullptr,
+    _LIBCPP_ASSERT_VALID_INPUT_RANGE(__count == 0 || std::to_address(__first) != nullptr,
                                      "passed nullptr with non-zero length in span's constructor (iterator, len)");
   }