libc: cleanup port preparation

- make port able to be prepared repeatedly
  Rpcgen refuses to overwrite an already existing header, so try to
  always remove it beforehand
- get rid of 'cp' warning 'cp: warning: source file
  'src/lib/libc/sys/sys/time.h' specified more than once'
- silence patch message 'patch unexpectedly ends in middle of line'

Fixes #3420.

repos/libports/ports/libc.hash

@@ -1 +1 @@
-12ac556f17580c447e7502e0485a662610f59c06
+60a83fda51da9b110e8b857e557f737a8310d00c

repos/libports/ports/libc.port

@@ -141,7 +141,7 @@ DIR_CONTENT(include/libc/sys) := \
                 utsname.h elf.h mtio.h _stdint.h atomic_common.h _ucontext.h \
                 _cpuset.h _bitset.h bitset.h _stdarg.h _uio.h auxv.h random.h \
                 _sockaddr_storage.h termios.h _termios.h _umtx.h kerneldump.h \
-                conf.h disk_zone.h counter.h time.h)
+                conf.h disk_zone.h counter.h)
 
 DIRS += include/libc/sys/disk
 DIR_CONTENT(include/libc/sys/disk) := $(D)/sys/sys/disk/*h
@@ -241,6 +241,7 @@ $(D)/include/rpcsvc/nis_object.x : $(DOWNLOADS)
 
 %.h: %.x
 	@$(MSG_GENERATE)$(notdir $@)
+	$(VERBOSE)rm -f $@
 	$(VERBOSE)rpcgen -C -h -DWANT_NFS3 $< -o $@
 
 generated_rpcsvc_files := \

repos/libports/src/lib/libc/patches/MB_CUR_MAX.patch

@@ -20,4 +20,5 @@
 -#define MB_CUR_MAX_L(x) ((size_t)___mb_cur_max_l(x))
 +/* ASCII only */
 +#define MB_CUR_MAX_L(x) 1
- 
+ 
+