tools/bpf/bpftool: Remove duplicate headers

Code cleanup: Remove duplicate headers which are included twice.

Signed-off-by: Jagadeesh Pagadala <[e-mail]>
Signed-off-by: Alexei Starovoitov <[e-mail]>
Reviewed-by: Quentin Monnet <[e-mail]>
Link: https://lore.kernel.org/bpf/[e-mail]

tools/bpf/bpftool/btf.c

···
 #include <linux/hashtable.h>
 #include <sys/types.h>
 #include <sys/stat.h>
-#include <unistd.h>
 
 #include "json_writer.h"
 #include "main.h"

tools/bpf/bpftool/gen.c

···
 #include <sys/types.h>
 #include <sys/stat.h>
 #include <sys/mman.h>
-#include <unistd.h>
 #include <bpf/btf.h>
 
 #include "bpf/libbpf_internal.h"

tools/bpf/bpftool/jit_disasm.c

···
 #include <stdio.h>
 #include <stdarg.h>
 #include <stdint.h>
-#include <stdio.h>
 #include <stdlib.h>
 #include <assert.h>
 #include <unistd.h>