perf jit: Add missing curly braces

perf jit: Add missing curly braces

It doesn't change the runtime behavior, but my static checker complains
that curly braces were intended.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: kernel-janitors@vger.kernel.org
Link: http://lkml.kernel.org/r/20160715210712.GA19522@mwanda
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>