kbuild: remove redundant target cleaning on failure

Since commit 9c2af1c737 ("kbuild: add .DELETE_ON_ERROR special
target"), the target file is automatically deleted on failure.

The boilerplate code

  ... || { rm -f $@; false; }

is unneeded.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>

arch/sh/tools/Makefile

@@ -13,4 +13,4 @@
 include/generated/machtypes.h: $(src)/gen-mach-types $(src)/mach-types
 	@echo '  Generating $@'
 	$(Q)mkdir -p $(dir $@)
-	$(Q)LC_ALL=C $(AWK) -f $^ > $@ || { rm -f $@; /bin/false; }
+	$(Q)LC_ALL=C $(AWK) -f $^ > $@