perf tools: Add include/err.h into MANIFEST

Otherwise the tarpkg is incomplete (tarpkg tests fails).
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Wang Nan <wangnan0@huawei.com>
Fixes: 01ca9fd4 ("tools: Add err.h with ERR_PTR PTR_ERR interface")
Link: http://lkml.kernel.org/r/1442846143-8556-1-git-send-email-jolsa@kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/MANIFEST

@@ -50,6 +50,7 @@ tools/include/linux/poison.h
 tools/include/linux/rbtree.h
 tools/include/linux/rbtree_augmented.h
 tools/include/linux/types.h
+tools/include/linux/err.h
 include/asm-generic/bitops/arch_hweight.h
 include/asm-generic/bitops/const_hweight.h
 include/asm-generic/bitops/fls64.h