kernel-yocto: explicitly trap subcommand errors

To trap errors and halt processing, do_kernel_metadata was recently
switched to exit on any non zero return code. While the concept is
sound, there are subcommands that have legitimate non-zero return
codes.

Instead of removing set +e, we'll explicitly check the return code
of the commands that can error, and throw a bbfatal to alert the
user.

(From OE-Core rev: a4705e62d0973c290011fc0d250501d358b659e8)

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

@@ -61,6 +61,7 @@ def get_machine_branch(d, default):
     return default
 
 do_kernel_metadata() {
+	set +e
 	cd ${S}
 	export KMETA=${KMETA}
 
@@ -148,12 +149,18 @@ do_kernel_metadata() {
 	elements="`echo -n ${bsp_definition} ${sccs} ${patches} ${KERNEL_FEATURES}`"
 	if [ -n "${elements}" ]; then
 		scc --force -o ${S}/${meta_dir}:cfg,meta ${includes} ${bsp_definition} ${sccs} ${patches} ${KERNEL_FEATURES}
+		if [ $? -ne 0 ]; then
+			bbfatal_log "Could not generate configuration queue for ${KMACHINE}."
+		fi
 	fi
 
 	# run2: only generate patches for elements that have been passed on the SRC_URI
 	elements="`echo -n ${sccs} ${patches} ${KERNEL_FEATURES}`"
 	if [ -n "${elements}" ]; then
 		scc --force -o ${S}/${meta_dir}:patch --cmds patch ${includes} ${sccs} ${patches} ${KERNEL_FEATURES}
+		if [ $? -ne 0 ]; then
+			bbfatal_log "Could not generate configuration queue for ${KMACHINE}."
+		fi
 	fi
 }