Remove unnecessary quoting from twres path

The C flag defines already use -DVAR=\"..\", so stripping these extra quotes
should not affect those defines.

The makefile does not need the quoting at all.

Makefile example output...
before: mkdir -p (omitted)/recovery/root"/twres/"
after:  mkdir -p (omitted)/recovery/root/twres/

Change-Id: I8f557662eb18b5ea40b63bc055d12be4440251e6
diff --git a/Android.mk b/Android.mk
index 6d9959c..e0f7848 100644
--- a/Android.mk
+++ b/Android.mk
@@ -35,7 +35,7 @@
 
 include $(CLEAR_VARS)
 
-TWRES_PATH := "/twres/"
+TWRES_PATH := /twres/
 TWHTCD_PATH := $(TWRES_PATH)htcd/
 
 TARGET_RECOVERY_GUI := true