zdb: Fix zdb '-O|-r' options with -e/exported zpool

zdb with '-e' or exported zpool doesn't work along with
'-O' and '-r' options as we process them before '-e' has
been processed.

Below errors are seen:

~> zdb -e pool-mds65/mdt65 -O oi.9/0x200000009:0x0:0x0
failed to hold dataset 'pool-mds65/mdt65': No such file or directory

~> zdb -e pool-oss0/ost0 -r file1 /tmp/filecopy1 -p.
failed to hold dataset 'pool-oss0/ost0': No such file or directory
zdb: internal error: No such file or directory

We need to make sure to process '-O|-r' options after the
'-e' option has been processed, which imports the pool to
the namespace if it's not in the cachefile.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Akash B <akash-b@hpe.com>
Closes openzfs#15532

cmd/zdb/zdb.c

@@ -9164,22 +9164,6 @@ main(int argc, char **argv)
 	if (dump_opt['l'])
 		return (dump_label(argv[0]));
 
-	if (dump_opt['O']) {
-		if (argc != 2)
-			usage();
-		dump_opt['v'] = verbose + 3;
-		return (dump_path(argv[0], argv[1], NULL));
-	}
-	if (dump_opt['r']) {
-		target_is_spa = B_FALSE;
-		if (argc != 3)
-			usage();
-		dump_opt['v'] = verbose;
-		error = dump_path(argv[0], argv[1], &object);
-		if (error != 0)
-			fatal("internal error: %s", strerror(error));
-	}
-
 	if (dump_opt['X'] || dump_opt['F'])
 		rewind = ZPOOL_DO_REWIND |
 		    (dump_opt['X'] ? ZPOOL_EXTREME_REWIND : 0);
@@ -9280,6 +9264,29 @@ main(int argc, char **argv)
 		searchdirs = NULL;
 	}
 
+	/*
+	 * We need to make sure to process -O option or call
+	 * dump_path after the -e option has been processed,
+	 * which imports the pool to the namespace if it's
+	 * not in the cachefile.
+	 */
+	if (dump_opt['O']) {
+		if (argc != 2)
+			usage();
+		dump_opt['v'] = verbose + 3;
+		return (dump_path(argv[0], argv[1], NULL));
+	}
+
+	if (dump_opt['r']) {
+		target_is_spa = B_FALSE;
+		if (argc != 3)
+			usage();
+		dump_opt['v'] = verbose;
+		error = dump_path(argv[0], argv[1], &object);
+		if (error != 0)
+			fatal("internal error: %s", strerror(error));
+	}
+
 	/*
 	 * import_checkpointed_state makes the assumption that the
 	 * target pool that we pass it is already part of the spa