[PATCH (mtd-utils)] Makefile: fix "make clean" for old GNU find

[Brian Norris]

findutils v4.1.x does not have the `-exec CMD {} +' syntax. We can just as
easily use the `-exec CMD {} \;' syntax. However, it will launch a lot more
`rm' processes...

RHEL 4 still uses findutils 4.1.20 and gets errors like this:

  $ make clean
  rm -f /XXX/mtd-utils/*.o /XXX/mtd-utils/ftl_format  ...
  find: missing argument to `-exec'
  make: *** [clean] Error 1

Signed-off-by: Brian Norris <computersforpeace at gmail.com>
---
 Makefile |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/Makefile b/Makefile
index 17a1216..0cbbecc 100644
--- a/Makefile
+++ b/Makefile
@@ -53,7 +53,7 @@ endif
 	@if test -d "$(BUILDDIR)/"; then \
 		find $(BUILDDIR)/ -xdev \
 			'(' -name '*.[ao]' -o -name '.*.c.dep' ')' \
-			-exec rm -f {} + ; \
+			-exec rm -f {} \; ; \
 	fi
 	rm -f $(BUILDDIR)/include/version.h
 	$(MAKE) -C $(TESTS) clean