qtuio: add error handling to for loop

Also remove unneeded sub-shell usage in the build and installation
steps. It is kept for the configure step as it is actually useful, and
works fine because "|| exit 1" is outside the sub-shell.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Acked-by: "Yann E. MORIN" <yann.morin.1998@free.fr>

package/qtuio/qtuio.mk

@@ -19,7 +19,7 @@ QTUIO_EXAMPLES = dials fingerpaint knobs pinchzoom
 ifeq ($(BR2_QTUIO_EXAMPLES),y)
 define QTUIO_CONFIGURE_EXAMPLES
 	for example in $(QTUIO_EXAMPLES) ; do \
-		(cd $(@D)/examples/$${example} && $(TARGET_MAKE_ENV) $(QT_QMAKE)) ; \
+		(cd $(@D)/examples/$${example} && $(TARGET_MAKE_ENV) $(QT_QMAKE)) || exit 1; \
 	done
 endef
 endif
@@ -32,7 +32,7 @@ endef
 ifeq ($(BR2_QTUIO_EXAMPLES),y)
 define QTUIO_BUILD_EXAMPLES
 	for example in $(QTUIO_EXAMPLES) ; do \
-		($(MAKE) -C $(@D)/examples/$${example}) ; \
+		$(MAKE) -C $(@D)/examples/$${example} || exit 1; \
 	done
 endef
 endif
@@ -46,7 +46,7 @@ endef
 ifeq ($(BR2_QTUIO_EXAMPLES),y)
 define QTUIO_INSTALL_EXAMPLES
 	for example in $(QTUIO_EXAMPLES) ; do \
-		($(INSTALL) -D -m 0755 $(@D)/examples/$${example}/$${example} $(TARGET_DIR)/usr/share/qtuio/$${example}) ; \
+		$(INSTALL) -D -m 0755 $(@D)/examples/$${example}/$${example} $(TARGET_DIR)/usr/share/qtuio/$${example} || exit 1 ; \
 	done
 endef
 endif