MIPS: Minor-key-ify four stubs.

src/mips64/macro-assembler-mips64.cc

Index: src/mips64/macro-assembler-mips64.cc
diff --git a/src/mips64/macro-assembler-mips64.cc b/src/mips64/macro-assembler-mips64.cc
index 87124dca14688ae64191e631396c48b249c2b082..0c490dd5f1801e1a975e5f118fef7a646e4c8613 100644
--- a/src/mips64/macro-assembler-mips64.cc
+++ b/src/mips64/macro-assembler-mips64.cc
@@ -400,8 +400,7 @@ void MacroAssembler::RememberedSetHelper(Register object,  // For debug tests.
     Ret(eq, t8, Operand(zero_reg));
   }
   push(ra);
-  StoreBufferOverflowStub store_buffer_overflow =
-      StoreBufferOverflowStub(isolate(), fp_mode);
+  StoreBufferOverflowStub store_buffer_overflow(isolate(), fp_mode);
   CallStub(&store_buffer_overflow);
   pop(ra);
   bind(&done);