Use String8/16 c_str [tools]

Bug: 295394788
Test: make checkbuild
Change-Id: I82d6899d8c15a10b15399c39177290012bb5f13b
Merged-In: I82d6899d8c15a10b15399c39177290012bb5f13b
diff --git a/tools/split-select/SplitDescription.cpp b/tools/split-select/SplitDescription.cpp
index 99bc23d..4e2b48e 100644
--- a/tools/split-select/SplitDescription.cpp
+++ b/tools/split-select/SplitDescription.cpp
@@ -134,8 +134,8 @@
     String8 configStr;
     String8 extensionStr;
     if (index >= 0) {
-        configStr.setTo(str.string(), index);
-        extensionStr.setTo(str.string() + index + 1);
+        configStr.setTo(str.c_str(), index);
+        extensionStr.setTo(str.c_str() + index + 1);
     } else {
         configStr.setTo(str);
     }