Remove spurious references to kEmitCompilerReadBarrier in MIPS.

We do not support read barriers on MIPS code generators yet.

Also, wrap some long lines in the MIPS64 code generator.

Change-Id: Ia2755590afa60eb9c8fb547e059146ab6518372b
diff --git a/compiler/optimizing/code_generator_mips.cc b/compiler/optimizing/code_generator_mips.cc
index 99a0982..5dc101b 100644
--- a/compiler/optimizing/code_generator_mips.cc
+++ b/compiler/optimizing/code_generator_mips.cc
@@ -3902,9 +3902,9 @@
 }
 
 void LocationsBuilderMIPS::VisitLoadString(HLoadString* load) {
-  LocationSummary::CallKind call_kind = (!load->IsInDexCache() || kEmitCompilerReadBarrier)
-      ? LocationSummary::kCallOnSlowPath
-      : LocationSummary::kNoCall;
+  LocationSummary::CallKind call_kind = load->IsInDexCache()
+      ? LocationSummary::kNoCall
+      : LocationSummary::kCallOnSlowPath;
   LocationSummary* locations = new (GetGraph()->GetArena()) LocationSummary(load, call_kind);
   locations->SetInAt(0, Location::RequiresRegister());
   locations->SetOut(Location::RequiresRegister());