perf tools: Move cmd_version() to builtin-version.c

Move cmd_version() to its own file so that help.c can be moved to a
library.

Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/e908b1b68f20ab6d8d33941d5571c23110622e60.1449548395.git.jpoimboe@redhat.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/Build

@@ -20,6 +20,7 @@ perf-y += builtin-kvm.o
 perf-y += builtin-inject.o
 perf-y += builtin-mem.o
 perf-y += builtin-data.o
+perf-y += builtin-version.o
 
 perf-$(CONFIG_AUDIT) += builtin-trace.o
 perf-$(CONFIG_LIBELF) += builtin-probe.o

tools/perf/builtin-version.c

@@ -0,0 +1,10 @@
+#include "util/util.h"
+#include "builtin.h"
+#include "perf.h"
+
+int cmd_version(int argc __maybe_unused, const char **argv __maybe_unused,
+		const char *prefix __maybe_unused)
+{
+	printf("perf version %s\n", perf_version_string);
+	return 0;
+}

tools/perf/util/help.c

@@ -332,10 +332,3 @@ const char *help_unknown_cmd(const char *cmd)
 
 	exit(1);
 }
-
-int cmd_version(int argc __maybe_unused, const char **argv __maybe_unused,
-		const char *prefix __maybe_unused)
-{
-	printf("perf version %s\n", perf_version_string);
-	return 0;
-}