emulator: fix a typo when copying userdata.img

replaced TARGET_CPU_ADI with TARGET_CPU_ABI

BUG: 110492064

this cl does not impact real devices

Test:
nohup make -j100 ANDROID_USE_BUILDCACHE=false PRODUCT-sdk_gphone_x86-sdk_addon showcommands dist DIST_DIR=${PWD}/dist/x86 sdk_repo
unzip the image package sdk-repo-linux-system-images-eng.zip and  make sure userdata.img is inside

Change-Id: I24101c78d789c9b72132efc41a2e98d5274b5ff1