debugfs: handle out of memory condition

If malloc fails, properly handle the error condition.

Signed-off-by: Tobias Stoeckmann <tobias@stoeckmann.org>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
diff --git a/debugfs/extent_inode.c b/debugfs/extent_inode.c
index 8b22f5e..c7a92a7 100644
--- a/debugfs/extent_inode.c
+++ b/debugfs/extent_inode.c
@@ -97,6 +97,11 @@
 
 	orig_prompt = ss_get_prompt(sci_idx);
 	extent_prompt = malloc(strlen(orig_prompt) + 32);
+	if (extent_prompt == NULL) {
+		com_err(argv[1], retval, "out of memory");
+		return;
+	}
+
 	strcpy(extent_prompt, orig_prompt);
 	cp = strchr(extent_prompt, ':');
 	if (cp)