patch 8.2.5122: lisp indenting my run over the end of the line

Problem:    Lisp indenting my run over the end of the line.
Solution:   Check for NUL earlier.
diff --git a/src/indent.c b/src/indent.c
index 794fa2c..fa177bc 100644
--- a/src/indent.c
+++ b/src/indent.c
@@ -2029,6 +2029,8 @@
 			    }
 			}
 		    }
+		    if (*that == NUL)
+			break;
 		}
 		if (*that == '(' || *that == '[')
 		    ++parencount;