kernel-yocto: exit on non-zero return code

Historically the processing of kernel meta data contained some
commands that exited with a non-zero return code. Special processing
was required to properly deal with their exit.

That is no longer true, and instead of handling all return codes
and doing an explicit 'exit' call, we can remove set -e from the
routine and have all errors be trapped and stop processing.

(From OE-Core rev: 476ffd57cf5b6fba40d4e3f5dd913824ab8a8d3d)

Signed-off-by: Bruce Ashfield <bruce.ashfield@windriver.com>
Signed-off-by: Ross Burton <ross.burton@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/classes/kernel-yocto.bbclass

@@ -61,7 +61,6 @@ def get_machine_branch(d, default):
     return default
 
 do_kernel_metadata() {
-	set +e
 	cd ${S}
 	export KMETA=${KMETA}