ueventd: replace char* with std::string in struct uevent

Bug: 36250207

Test: Boot bullhead
Test: Boot sailfish, observe no boot time regression
Test: init unit tests

Change-Id: Ib82833bea56bdafbe1d7a045126aaa91a8725d98
diff --git a/init/devices.h b/init/devices.h
index f6183c9..c12ba9d 100644
--- a/init/devices.h
+++ b/init/devices.h
@@ -36,12 +36,12 @@
 };
 
 struct uevent {
-    const char* action;
-    const char* path;
-    const char* subsystem;
-    const char* firmware;
-    const char* partition_name;
-    const char* device_name;
+    std::string action;
+    std::string path;
+    std::string subsystem;
+    std::string firmware;
+    std::string partition_name;
+    std::string device_name;
     int partition_num;
     int major;
     int minor;