tools/runqslower: Drop copy/pasted BPF_F_CURRENT_CPU definiton

With BPF_F_CURRENT_CPU being an enum, it is now captured in vmlinux.h and is
readily usable by runqslower. So drop local copy/pasted definition in favor of
the one coming from vmlinux.h.
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20200303003233.3496043-4-andriin@fb.com

tools/bpf/runqslower/runqslower.bpf.c

@@ -6,9 +6,6 @@
 
 #define TASK_RUNNING 0
 
-#define BPF_F_INDEX_MASK		0xffffffffULL
-#define BPF_F_CURRENT_CPU		BPF_F_INDEX_MASK
-
 const volatile __u64 min_us = 0;
 const volatile pid_t targ_pid = 0;