make these retry_write methods static so that they don't end up as symbols

apt-pkg/deb/dpkgpm.cc

@@ -163,7 +163,8 @@ pkgCache::VerIterator FindNowVersion(const pkgCache::PkgIterator &Pkg)
    return Ver;
 }
 									/*}}}*/
-ssize_t retry_write(int fd, const void *buf, size_t count)
+static ssize_t
+retry_write(int fd, const void *buf, size_t count)
 {
    int Res;
    ssize_t i = 0;

methods/rred.cc

@@ -227,7 +227,7 @@ struct EdCommand {
   char type;
 };
 #define IOV_COUNT 1024 /* Don't really want IOV_MAX since it can be arbitrarily large */
-ssize_t retry_writev(int fd, const struct iovec *iov, int iovcnt) {
+static ssize_t retry_writev(int fd, const struct iovec *iov, int iovcnt) {
 	ssize_t Res;
 	errno = 0;
 	ssize_t i = 0;