restore: fix resource handle leak.

CID:		1007784
MFC after:	5 days

sbin/restore/symtab.c

@@ -559,6 +559,7 @@ initsymtable(char *filename)
 		fprintf(stderr, "read: %s\n", strerror(errno));
 		panic("cannot read symbol table file %s\n", filename);
 	}
+	(void)close(fd);
 	switch (command) {
 	case 'r':
 		/*