make.defaults: disable USE=shm

Since Android is built w/System V features disabled, flip off this
flag as well.

Change-Id: Ic83c34d656bb9fccf3b56c9904495ec72652f24f
diff --git a/portage/make.defaults.in b/portage/make.defaults.in
index 7073df5..fce3aaa 100644
--- a/portage/make.defaults.in
+++ b/portage/make.defaults.in
@@ -15,6 +15,9 @@
 # We do not use/support PAM under Android.
 USE="${USE} -pam"
 
+# Android does not have support for SystemV shared memory or ipc.
+USE="${USE} -shm"
+
 # No support for translations.  You'll have to handle them yourself.
 USE="${USE} -nls"