android envsetup: Stop explicitly setting host_arch when target_arch=x86.

The explicit setting seems to match the default value for host_arch in
build/common.gypi close to line 110, and it's not set explicitly for other
target_archs, so this looks like an oversight. It's been this way since this
file was added in r148790 18 months ago.

No intended behavior change.

BUG=330631

Review URL: https://codereview.chromium.org/142023006

git-svn-id: http://src.chromium.org/svn/trunk/src/build@248188 4ff67af0-8c30-449e-8e8b-ad334ec8d88c

android/envsetup_functions.sh

@@ -98,9 +98,6 @@ ${ANDROID_SDK_BUILD_TOOLS_VERSION}
       DEFINES+=" target_arch=arm"
       ;;
     "x86")
-      host_arch=$(uname -m | sed -e \
-        's/i.86/ia32/;s/x86_64/x64/;s/amd64/x64/;s/arm.*/arm/;s/i86pc/ia32/')
-      DEFINES+=" host_arch=${host_arch}"
       DEFINES+=" target_arch=ia32"
       ;;
     "mips")