patch: minor documentation fix. Fix @return description of git_patch_num_lines_in_hunk.
diff --git a/include/git2/patch.h b/include/git2/patch.h
index 790cb74..4eb9f02 100644
--- a/include/git2/patch.h
+++ b/include/git2/patch.h
@@ -191,7 +191,7 @@ GIT_EXTERN(int) git_patch_get_hunk(
*
* @param patch The git_patch object
* @param hunk_idx Index of the hunk
- * @return Number of lines in hunk or -1 if invalid hunk index
+ * @return Number of lines in hunk or GIT_ENOTFOUND if invalid hunk index
*/
GIT_EXTERN(int) git_patch_num_lines_in_hunk(
const git_patch *patch,