drm_hwcomposer: Fix property_get() linux impl.

Bad implementation was found during code surfing.
At this moment function is used only as a stub for CI.

Signed-off-by: Roman Stratiienko <r.stratiienko@gmail.com>
diff --git a/utils/properties.h b/utils/properties.h
index 8d883eb..c8ddbae 100644
--- a/utils/properties.h
+++ b/utils/properties.h
@@ -18,9 +18,8 @@
 auto inline property_get(const char *name, char *value,
                          const char *default_value) -> int {
   char *prop = std::getenv(name);
-  if (prop == nullptr) {
-    snprintf(value, PROPERTY_VALUE_MAX, "%s", default_value);
-  }
+  snprintf(value, PROPERTY_VALUE_MAX, "%s",
+           (prop == nullptr) ? default_value : prop);
   return static_cast<int>(strlen(value));
 }