controllers: Simplify fullpath definition

PATH_MAX has been in <limits.h> in all libc for a long time.

Acked-by: Jan Stancek <jstancek@redhat.com>
Acked-by: Cyril Hrubis <chrubis@suse.cz>
Signed-off-by: Petr Vorel <pvorel@suse.cz>
diff --git a/testcases/kernel/controllers/libcontrollers/libcontrollers.h b/testcases/kernel/controllers/libcontrollers/libcontrollers.h
index cdde9f9..f999f70 100644
--- a/testcases/kernel/controllers/libcontrollers/libcontrollers.h
+++ b/testcases/kernel/controllers/libcontrollers/libcontrollers.h
@@ -42,11 +42,7 @@
 #include <sys/types.h>
 #include <unistd.h>
 
-#ifdef PATH_MAX
 char fullpath[PATH_MAX];
-#else
-char fullpath[1024]; /* Guess */
-#endif
 
 int FLAG;
 volatile int timer_expired;