Fix warning: overriding commands for target

Change-Id: I00fb4d6a8ff388722b75de9a0f4316619aaf9320
diff --git a/build/run-on-host.mk b/build/run-on-host.mk
index f016361..dc7e5d5 100644
--- a/build/run-on-host.mk
+++ b/build/run-on-host.mk
@@ -14,6 +14,10 @@
 # limitations under the License.
 #
 
+# Include once
+ifneq ($(bionic_run_on_host_mk_included),true)
+bionic_run_on_host_mk_included:=true
+
 ifneq ($(TARGET_ARCH),$(filter $(TARGET_ARCH),arm mips x86))
 LINKER = linker64
 else
@@ -37,3 +41,4 @@
 	  ln -fs `realpath $(TARGET_OUT)/lib64` /system/; \
 	fi
 endif
+endif