clang -cc1as: Remove a redundant initSections call

`Parser->Run(Opts.NoInitialTextSection)` calls initSections. Remove a
redundant initSections to remove an extra FT_Align fragment, observed
when investigating a missing MCOrgFragment relaxation issue
ClangBuiltLinux/linux#2116

Author: MaskRay

clang/tools/driver/cc1as_main.cpp

@@ -577,7 +577,6 @@ static bool ExecuteAssemblerImpl(AssemblerInvocation &Opts,
     Triple T(Opts.Triple);
     Str.reset(TheTarget->createMCObjectStreamer(
         T, Ctx, std::move(MAB), std::move(OW), std::move(CE), *STI));
-    Str->initSections(Opts.NoExecStack, *STI);
     if (T.isOSBinFormatMachO() && T.isOSDarwin()) {
       Triple *TVT = Opts.DarwinTargetVariantTriple
                         ? &*Opts.DarwinTargetVariantTriple