ANDROID: x86: Remove a useless warning message

While we wait for a clang prebuilt with asm-goto support, we have
removed the kbuild's detection of a clang without asm-goto (the
kernel builds fine without it), so we don't need to see the same
warning about not having the compiler feature fill the kernel build
log, which potentially hides other issues.

This patch should be reverted when the new clang prebuilt lands and
we have reverted the other reverts.

Bug: 120440614
Test: make ARCH=x86_64 x86_64_cuttlefish_defconfig && make ARCH=x86_64
Change-Id: I26aee5b9dd291f27b950dee4b0c64471d972ddb5
Signed-off-by: Alistair Strachan <astrachan@google.com>