Fix make spotless; from Olaf Hering

diff --git a/klibc/Makefile b/klibc/Makefile
index 55bb5bf..b3517cd 100644
--- a/klibc/Makefile
+++ b/klibc/Makefile
@@ -157,6 +157,7 @@
 	rm -f sha1hash errlist.c
 
 spotless: clean
+	rm -f include/klibc/havesyscall.h syscalls.nrs
 	find . \( -name \*~ -o -name '.*.d' \) -not -type d -print0 | \
 		xargs -0rt rm -f