Don't include headers in depend target

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
diff --git a/Makefile b/Makefile
index cd061ad..14fcdd1 100644
--- a/Makefile
+++ b/Makefile
@@ -46,7 +46,7 @@
 	$(QUIET_CC)$(CC) $(CFLAGS) -o $@ $(filter %.o,$^) $(EXTLIBS) -lpthread -lm -ldl -laio -lrt
 
 depend:
-	$(QUIET_DEP)$(CC) -MM $(ALL_CFLAGS) *.c engines/*.c crc/*.[ch] 1> .depend
+	$(QUIET_DEP)$(CC) -MM $(ALL_CFLAGS) *.c engines/*.c crc/*.c 1> .depend
 
 $(PROGS): depend