UPSTREAM: kheaders: remove meaningless -R option of 'ls'

The -R option of 'ls' is supposed to be used for directories.

   -R, --recursive
          list subdirectories recursively

Since 'find ... -type f' only matches to regular files, we do not
expect directories passed to the 'ls' command here.

Giving -R is harmless at least, but unneeded.

Change-Id: I73588f18e40824ccecc4149fbc467015b5c5e142
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org>
(cherry picked from commit b60b7c2ea9b7f854d457fefd592c77f621a86580)
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>