Use String8/16 c_str [drm]

Bug: 295394788
Test: make checkbuild
Change-Id: I8446de3a553a3ddce2da5c4551127039638e0a98
diff --git a/drm/1.0/default/SharedLibrary.cpp b/drm/1.0/default/SharedLibrary.cpp
index 0a942cd..c9b5389 100644
--- a/drm/1.0/default/SharedLibrary.cpp
+++ b/drm/1.0/default/SharedLibrary.cpp
@@ -26,7 +26,7 @@
 namespace helper {
 
 SharedLibrary::SharedLibrary(const String8& path) {
-    mLibHandle = dlopen(path.string(), RTLD_NOW);
+    mLibHandle = dlopen(path.c_str(), RTLD_NOW);
 }
 
 SharedLibrary::~SharedLibrary() {