Makefile: ensure that iowatcher gets cleaned

Signed-off-by: Jens Axboe <axboe@fb.com>
diff --git a/Makefile b/Makefile
index 458f237..fdbded0 100644
--- a/Makefile
+++ b/Makefile
@@ -79,6 +79,7 @@
 	-rm -f *.o $(PROGS) .depend btrace-1.0.tar.bz2
 	$(MAKE) -C btt clean
 	$(MAKE) -C btreplay clean
+	$(MAKE) -C iowatcher clean
 
 install: all
 	$(INSTALL) -m 755 -d $(DESTDIR)$(bindir)
diff --git a/iowatcher/Makefile b/iowatcher/Makefile
index 7b5101c..e0f34b2 100644
--- a/iowatcher/Makefile
+++ b/iowatcher/Makefile
@@ -1,4 +1,4 @@
-C      = gcc
+CC      = gcc
 CFLAGS  = -Wall -O0 -g -W
 ALL_CFLAGS = $(CFLAGS) -D_GNU_SOURCE -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64