(1) Do not check for ldconfig in checkpath()
(2) Handle EROFS in ensure_pathname_nonexisting().
    This is since ensure_pathname_nonexisting() will be called with
    	'/data.dpkg-tmp'
	'/data/data.dpkg-tmp'
	'/data/data/com.termux.dpkg-tmp'
	'/data/data/com.termux/files.dpkg-tmp'
	'/data/data/com.termux/files/usr.dpkg-tmp'
    and the first call will get a EROFS, read-only file system error.

diff -u -r ../dpkg-1.17.23/src/help.c ./src/help.c
--- ../dpkg-1.17.23/src/help.c	2014-12-27 17:21:19.000000000 -0500
+++ ./src/help.c	2015-01-01 19:08:58.868327880 -0500
@@ -89,12 +89,14 @@
     TAR,
     FIND,
     BACKEND,
+#ifndef __ANDROID__
     /* Mac OS X uses dyld (Mach-O) instead of ld.so (ELF), and does not have
      * an ldconfig. */
-#if defined(__APPLE__) && defined(__MACH__)
+# if defined(__APPLE__) && defined(__MACH__)
     "update_dyld_shared_cache",
-#else
+# else
     "ldconfig",
+# endif
 #endif
 #if BUILD_START_STOP_DAEMON
     "start-stop-daemon",
@@ -376,7 +378,7 @@
   debug(dbg_eachfile, "ensure_pathname_nonexisting '%s'", pathname);
   if (!rmdir(pathname))
     return; /* Deleted it OK, it was a directory. */
-  if (errno == ENOENT || errno == ELOOP) return;
+  if (errno == ENOENT || errno == ELOOP || errno == EROFS) return;
   if (errno == ENOTDIR) {
     /* Either it's a file, or one of the path components is. If one
      * of the path components is this will fail again ... */