Bail out with arg error if specifying a size larger than the file

system size

This is to spot obvious typos

bin/varnishd/storage/stevedore_utils.c

@@ -182,6 +182,10 @@ STV_FileSize(int fd, const char *size, unsigned *granularity, const char *ctx)
 		if (l < 1024*1024)
 			ARGV_ERR("(%s) size \"%s\": too small, "
 			    "did you forget to specify M or G?\n", ctx, size);
+
+		if (l > fssize)
+			ARGV_ERR("(%s) size \"%s\": larger than file system\n",
+			    ctx, size);
 	}
 
 	/*