perf build: Rename feature_print_var_code to print_var_code

perf build: Rename feature_print_var_code to print_var_code

As it has nothing to do with features and won't be moved
into tools/build.

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-6qgf37nss4wwjatgj5i4ng0o@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>