reflog-walk: build fixes

Dependency on reflog-walk.h was missing in the Makefile, and
reflog-walk.c did not even include it.
Signed-off-by: NJunio C Hamano <junkio@cox.net>

Makefile

@@ -241,7 +241,7 @@ LIB_H = \
 	diff.h object.h pack.h pkt-line.h quote.h refs.h list-objects.h sideband.h \
 	run-command.h strbuf.h tag.h tree.h git-compat-util.h revision.h \
 	tree-walk.h log-tree.h dir.h path-list.h unpack-trees.h builtin.h \
-	utf8.h
+	utf8.h reflog-walk.h
 
 DIFF_OBJS = \
 	diff.o diff-lib.o diffcore-break.o diffcore-order.o \

reflog-walk.c

@@ -4,6 +4,7 @@
 #include "diff.h"
 #include "revision.h"
 #include "path-list.h"
+#include "reflog-walk.h"
 
 struct complete_reflogs {
 	char *ref;