perf build: Move features build output under features directory

perf build: Move features build output under features directory

Following commit introduced features build dump:
  443a70541c56 perf tools: Output feature detection's gcc output to a file

Moving them into to have code more compact and renaming build dump
files. For each feature 'test-X' new file 'test-X.make.output' is
created and contains the build out.  It's created in the same directory
as the feature itself.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: David Ahern <david.ahern@oracle.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/n/tip-dk6svnhcephrzgz4mfpcmtm7@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>