Allow re-targeting of naclports install

libraries/glibc-compat/nacl-glibc-compat.sh

Index: libraries/glibc-compat/nacl-glibc-compat.sh
diff --git a/libraries/glibc-compat/nacl-glibc-compat.sh b/libraries/glibc-compat/nacl-glibc-compat.sh
index 52f01a3eb297205eed5d2d00656400a42b94918d..258e0152011633ea355ab2ec373a10cdf2650133 100755
--- a/libraries/glibc-compat/nacl-glibc-compat.sh
+++ b/libraries/glibc-compat/nacl-glibc-compat.sh
@@ -35,10 +35,10 @@ CustomConfigureStep() {
 }
 
 CustomInstallStep() {
-  Remove ${NACL_SDK_USR_LIB}/${LIB_GLIBC_COMPAT}
-  Remove ${NACL_SDK_USR_INCLUDE}/glibc-compat
-  install -m 644 out/${LIB_GLIBC_COMPAT} ${NACL_SDK_USR_LIB}/${LIB_GLIBC_COMPAT}
-  cp -r include ${NACL_SDK_USR_INCLUDE}/glibc-compat
+  Remove ${NACLPORTS_LIBDIR}/${LIB_GLIBC_COMPAT}
+  Remove ${NACLPORTS_INCLUDE}/glibc-compat
+  install -m 644 out/${LIB_GLIBC_COMPAT} ${NACLPORTS_LIBDIR}/${LIB_GLIBC_COMPAT}
+  cp -r include ${NACLPORTS_INCLUDE}/glibc-compat
 }
 
 CustomPackageInstall() {