Fix memory allocation issue

Author: dgovil

pxr/base/arch/darwin.mm

@@ -7,14 +7,12 @@
 
 #include "pxr/base/arch/darwin.h"
 #import <Foundation/Foundation.h>
-#include <string>
 
 PXR_NAMESPACE_OPEN_SCOPE
 
 
 const char* Arch_DarwinGetTemporaryDirectory() {
-    std::string tmpDir = [NSTemporaryDirectory() UTF8String];
-    return tmpDir.c_str();
+    return [NSTemporaryDirectory() UTF8String];
 }
 
 PXR_NAMESPACE_CLOSE_SCOPE

pxr/base/arch/fileSystem.cpp

@@ -736,7 +736,7 @@ Arch_InitTmpDir()
     _TmpDir = _strdup(ArchWindowsUtf16ToUtf8(tmpPath).c_str());
 #elif defined(ARCH_OS_DARWIN)
     // On Apple platforms, we use the system APIs to get the designated temp directory
-    _TmpDir = Arch_DarwinGetTemporaryDirectory();
+    _TmpDir = strdup(Arch_DarwinGetTemporaryDirectory());
 #else
     const std::string tmpdir = ArchGetEnv("TMPDIR");
     if (!tmpdir.empty()) {