PPC: Refine "Deprecate unused RelocInfo::CONSTRUCT_CALL mode."

R=mstarzinger@chromium.org, joransiu@ca.ibm.com, jyan@ca.ibm.com, michael_dawson@ca.ibm.com
BUG=

Review URL: https://codereview.chromium.org/1487873002

Cr-Commit-Position: refs/heads/master@{#32436}

src/ppc/macro-assembler-ppc.cc

@@ -50,8 +50,7 @@ void MacroAssembler::Jump(intptr_t target, RelocInfo::Mode rmode,
 
   if (cond != al) b(NegateCondition(cond), &skip, cr);
 
-  DCHECK(rmode == RelocInfo::CODE_TARGET || rmode == RelocInfo::RUNTIME_ENTRY ||
-         rmode == RelocInfo::CODE_TARGET);
+  DCHECK(rmode == RelocInfo::CODE_TARGET || rmode == RelocInfo::RUNTIME_ENTRY);
 
   mov(ip, Operand(target, rmode));
   mtctr(ip);