perf tools: Do not create kernel maps in sample__resolve()

perf tools: Do not create kernel maps in sample__resolve()

There's no need for kernel maps to be allocated at this point - sample
processing.

We search for kernel maps using the kernel map_groups in machine::kmaps
which is static. If vmlinux maps for any reason still don't exist, the
search correctly fails because they are not in the map group.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20180215122635.24029-9-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>