Use String8/16 c_str [camera]

Bug: 295394788
Test: make checkbuild
Change-Id: I321053f5a82ca2e1ad9ea447f96e81a87c3fcfe0
diff --git a/camera/CameraBase.cpp b/camera/CameraBase.cpp
index be1d4c5..1af899d 100644
--- a/camera/CameraBase.cpp
+++ b/camera/CameraBase.cpp
@@ -185,7 +185,7 @@
         c->mStatus = NO_ERROR;
     } else {
         ALOGW("An error occurred while connecting to camera %d: %s", cameraId,
-                (cs == nullptr) ? "Service not available" : ret.toString8().string());
+                (cs == nullptr) ? "Service not available" : ret.toString8().c_str());
         c.clear();
     }
     return c;
@@ -270,7 +270,7 @@
             &count);
     if (!res.isOk()) {
         ALOGE("Error reading number of cameras: %s",
-                res.toString8().string());
+                res.toString8().c_str());
         count = 0;
     }
     return count;