patch 8.1.0270: checking for a Tab in a line could be faster

Problem:    Checking for a Tab in a line could be faster.
Solution:   Use strchr() instead of strrchr(). (closes #3312)

Author: brammool

src/ex_cmds.c

@@ -281,7 +281,7 @@ linelen(int *has_tab)
     *last = NUL;
     len = linetabsize(line);		/* get line length */
     if (has_tab != NULL)		/* check for embedded TAB */
-	*has_tab = (vim_strrchr(first, TAB) != NULL);
+	*has_tab = (vim_strchr(first, TAB) != NULL);
     *last = save;
 
     return len;

src/version.c

@@ -794,6 +794,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    270,
 /**/
     269,
 /**/