perf kvm: Fix stdin handling for 'kvm stat live' command

perf kvm: Fix stdin handling for 'kvm stat live' command

Currently the initial ~(ICANON | ECHO) terminal mode is not set, so we
dont get stdin data until we press ENTER.

Fixing this by early setting of the ~(ICANON | ECHO) mode and leaving
this mode for whole life of the command, because canonical mode is not
needed.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jean Pihet <jean.pihet@linaro.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1407747014-18394-16-git-send-email-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>