perf jit: Fix build issue on Ubuntu

perf jit: Fix build issue on Ubuntu

When building on Ubuntu 16.04, I get the following error:

Makefile:49: *** the openjdk development package appears to me missing, install and try again.  Stop.

The problem is that update-java-alternatives has multiple spaces between
fields, and cut treats each space as a new delimiter:

java-1.8.0-openjdk-ppc64el     1081       /usr/lib/jvm/java-1.8.0-openjdk-ppc64el

Fix this by using awk, which handles this fine.

Signed-off-by: Anton Blanchard <anton@samba.org>
Reviewed-by: Stephane Eranian <eranian@google.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1476325243-15788-1-git-send-email-anton@ozlabs.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>