linux-libc-headers: do_install: fix "Argument list too long" error

linux-libc-headers: do_install: fix "Argument list too long" error

There would be an "Argument list too long" error when the TMPDIR is in a
deep dir, for example, when "len(readlink -f TMPDIR) >= 350 (our
supported value is 410)". Use "$(foreach ,,$(shell echo))" to fix it.

There was already a patch which tried to fix this issue, so squash the
current change into the previous one as Bruce suggested.

[YOCTO #5138]

(From OE-Core rev: 4e10c45d7c61ac1ccf8b53ef525ca03d3d458bba)

Signed-off-by: Robert Yang <liezhi.yang@windriver.com>
Signed-off-by: Bruce Ashfield <bruce.ashfield@windriver.com>
Signed-off-by: Saul Wold <sgw@linux.intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>