qemu: delete rule target on error

Instruct make to remove any rule target on error. This prevetns
situation where there was an error during build but generated file still
stays behind.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
(cherry picked from commit 7dbbbb0c9e4313cf2d2f6559b7899259fb09eb63)

diff --git a/rules.mak b/rules.mak
index 16713bacd75601385738f442a8fb276270953d4a..5d9f684c24b68ddc0247c72e82693811c697e5b6 100644 (file)
--- a/rules.mak
+++ b/rules.mak
@@ -47,3 +47,6 @@ cc-option = $(if $(shell $(CC) $1 $2 -S -o /dev/null -xc /dev/null \
 %.h-timestamp: %.mak
        $(call quiet-command, sh $(SRC_PATH)/create_config < $< > $@, "  GEN   $*.h")
        @cmp $@ $*.h >/dev/null 2>&1 || cp $@ $*.h
+
+# will delete the target of a rule if commands exit with a nonzero exit status
+.DELETE_ON_ERROR: