perf tools: Do not manually count string lengths

Use strlen & macros instead of manually counting string lengths as
this is error prone and may lend to bugs.

Signed-off-by: Vincent Legoll <vincent.legoll@gmail.com>
Cc: Linus Torvalds <torvalds@osdl.org>
LKML-Reference: <4727185d0910130118m5387058dndb02ac9b384af9f0@mail.gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/tools/perf/util/cache.h b/tools/perf/util/cache.h
index f26172c..918eb37 100644
--- a/tools/perf/util/cache.h
+++ b/tools/perf/util/cache.h
@@ -5,6 +5,11 @@
 #include "strbuf.h"
 #include "../perf.h"
 
+#define CMD_EXEC_PATH "--exec-path"
+#define CMD_PERF_DIR "--perf-dir="
+#define CMD_WORK_TREE "--work-tree="
+#define CMD_DEBUGFS_DIR "--debugfs-dir="
+
 #define PERF_DIR_ENVIRONMENT "PERF_DIR"
 #define PERF_WORK_TREE_ENVIRONMENT "PERF_WORK_TREE"
 #define DEFAULT_PERF_DIR_ENVIRONMENT ".perf"