Revert "CID#705982 ensure umask for mkstemp"

This reverts commit 9ab99483.  Coverity warning
about mkstemp without umask appears to be bogus (cf.
<https://communities.coverity.com/message/6516> "Why are uses of mkstemp
'without securely setting umask first' being flagged?) and calling umask is not
MT-safe, see fdo#60338 "FILESAVE: Saved files have incorrect permissions on
linux."

bridges/source/cpp_uno/shared/vtablefactory.cxx

@@ -60,8 +60,6 @@
 
 #if defined USE_DOUBLE_MMAP
 #include <fcntl.h>
-#include <sys/types.h>
-#include <sys/stat.h>
 #endif
 
 using bridges::cpp_uno::shared::VtableFactory;
@@ -241,7 +239,6 @@ bool VtableFactory::createBlock(Block &block, sal_Int32 slotCount) const
     if (aSecurity.getHomeDir(strURLDirectory))
         osl::File::getSystemPathFromFileURL(strURLDirectory, strDirectory);
 
-    mode_t nOrigMode = umask(S_IRWXG | S_IRWXO);
     for (int i = strDirectory.isEmpty() ? 1 : 0; i < 2; ++i)
     {
         if (strDirectory.isEmpty())
@@ -293,7 +290,6 @@ bool VtableFactory::createBlock(Block &block, sal_Int32 slotCount) const
 
         strDirectory = OUString();
     }
-    umask(nOrigMode);
     if (!block.start || !block.exec || block.fd == -1)
     {
        //Fall back to non-doublemmaped allocation