8254661: arm32: additional cleanup after fixing SIGSEGV

Reviewed-by: ngasson, shade

src/hotspot/cpu/arm/interp_masm_arm.cpp

@@ -983,7 +983,7 @@ void InterpreterMacroAssembler::lock_object(Register Rlock) {
 
 // Unlocks an object. Used in monitorexit bytecode and remove_activation.
 //
-// Argument: R1: Points to BasicObjectLock structure for lock
+// Argument: R0: Points to BasicObjectLock structure for lock
 // Throw an IllegalMonitorException if object is not locked by current thread
 // Blows volatile registers R0-R3, Rtemp, LR. Calls VM.
 void InterpreterMacroAssembler::unlock_object(Register Rlock) {
@@ -996,8 +996,7 @@ void InterpreterMacroAssembler::unlock_object(Register Rlock) {
 
     const Register Robj = R2;
     const Register Rmark = R3;
-    const Register Rresult = R0;
-    assert_different_registers(Robj, Rmark, Rlock, R0, Rtemp);
+    assert_different_registers(Robj, Rmark, Rlock, Rtemp);
 
     const int obj_offset = BasicObjectLock::obj_offset_in_bytes();
     const int lock_offset = BasicObjectLock::lock_offset_in_bytes ();