patch 9.1.0374: wrong botline in BufEnter

Problem:  When :edit an existing buffer, line('w$') may return a
          wrong result.
Solution: Reset w_valid in curwin_init() (Jaehwang Jung)

`do_ecmd()` reinitializes the current window (`curwin_init()`) whose
`w_valid` field may have `VALID_BOTLINE` set. Resetting `w_botline`
without marking it as invalid makes subsequent `validate_botline()`
calls a no-op, thus resulting in wrong `line('w$')` value.

closes: #14642

Signed-off-by: Jaehwang Jung <tomtomjhj@gmail.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/src/vim.h b/src/vim.h
index 4507674..f359245 100644
--- a/src/vim.h
+++ b/src/vim.h
@@ -656,8 +656,8 @@
 #define VALID_VIRTCOL	0x04	// w_virtcol (file col) is valid
 #define VALID_CHEIGHT	0x08	// w_cline_height and w_cline_folded valid
 #define VALID_CROW	0x10	// w_cline_row is valid
-#define VALID_BOTLINE	0x20	// w_botine and w_empty_rows are valid
-#define VALID_BOTLINE_AP 0x40	// w_botine is approximated
+#define VALID_BOTLINE	0x20	// w_botline and w_empty_rows are valid
+#define VALID_BOTLINE_AP 0x40	// w_botline is approximated
 #define VALID_TOPLINE	0x80	// w_topline is valid (for cursor position)
 
 // Values for w_popup_flags.