Remove pointless code: Don't assign a value to a variable when we're

going to overwrite it with a new value a few lines later.

Visual inspection of the surrounding code indicates that the code does
what it's supposed to do; i.e., the pointless code wasn't supposed to
be doing something other than what it was doing.

CID:		3323
Found by:	Coverity Prevent(tm)

lib/libarchive/archive_write_disk.c

@@ -1267,7 +1267,6 @@ create_dir(struct archive_write_disk *a, char *path)
 
 	/* Check for special names and just skip them. */
 	slash = strrchr(path, '/');
-	base = strrchr(path, '/');
 	if (slash == NULL)
 		base = path;
 	else