HBSD: Fix "libarchive vulnerability 2"

Around a week or so ago, a report[2] was made public showing FreeBSD
susceptible to numerous vulnerabilities in freebsd-update, portsnap,
libarchive, bsdtar, and bspatch. At least one of the vulnerabilities
has been fixed due to libarchive being updated to 3.2.1 in both HEAD,
11-STABLE, and 10-STABLE.

This commit addresses one of the vulnerabilities in libarchive/bsdtar.
As I validate more vulnerabilities, more fixes may come.

[1]:
https://hardenedbsd.org/~shawn/vulns/freebsd/2016-07-29/libarchive.txt

Signed-off-by:	Shawn Webb <shawn.webb@hardenedbsd.org>
Reported-by:	Some anonymous person
MFC-to:		11-STABLE
MFC-to:		10-STABLE

contrib/libarchive/libarchive/archive_write_disk_posix.c

@@ -1796,7 +1796,7 @@ edit_deep_directories(struct archive_write_disk *a)
 	char *tail = a->name;
 
 	/* If path is short, avoid the open() below. */
-	if (strlen(tail) <= PATH_MAX)
+	if (strlen(tail) < PATH_MAX)
 		return;
 
 	/* Try to record our starting dir. */
@@ -1806,7 +1806,7 @@ edit_deep_directories(struct archive_write_disk *a)
 		return;
 
 	/* As long as the path is too long... */
-	while (strlen(tail) > PATH_MAX) {
+	while (strlen(tail) >= PATH_MAX) {
 		/* Locate a dir prefix shorter than PATH_MAX. */
 		tail += PATH_MAX - 8;
 		while (tail > a->name && *tail != '/')
@@ -2403,6 +2403,8 @@ check_symlinks(struct archive_write_disk *a)
 			/* We've hit a dir that doesn't exist; stop now. */
 			if (errno == ENOENT)
 				break;
+			else
+				return (ARCHIVE_FAILED);
 		} else if (S_ISLNK(st.st_mode)) {
 			if (c == '\0') {
 				/*