When user runs devshell in kernel recipe and compiles kernel,
this will fail by unrecognized option of LD.
----
$ make
...
arm-poky-linux-gnueabi-ld: unrecognized option '-Wl,-O1'
arm-poky-linux-gnueabi-ld: use the --help option for usage information
----
This set to empty LDFLAGS when user runs the devshell, and solve this problem.
(From OE-Core rev: e36ac3ab3a7fe02c7eeb3998ff33c001ab795841)
Signed-off-by: Nobuhiro Iwamatsu <nobuhiro.iwamatsu.yj@renesas.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>