Docstring improvements

* src/xdisp.c (syms_of_xdisp):
* src/keyboard.c (syms_of_keyboard):
Docstring improvements.

src/keyboard.c

@@ -12729,7 +12729,7 @@ Note that, when the current buffer contains one or more lines whose
 length is above `long-line-threshold', these hook functions are called
 with the buffer narrowed to a small portion around point (whose size
 is specified by `long-line-locked-narrowing-region-size'), and the
-narrowing is locked (see `narrow-to-region'), so that these hook
+narrowing is locked (see `narrowing-lock'), so that these hook
 functions cannot use `widen' to gain access to other portions of
 buffer text.
 
@@ -12751,7 +12751,7 @@ Note that, when the current buffer contains one or more lines whose
 length is above `long-line-threshold', these hook functions are called
 with the buffer narrowed to a small portion around point (whose size
 is specified by `long-line-locked-narrowing-region-size'), and the
-narrowing is locked (see `narrow-to-region'), so that these hook
+narrowing is locked (see `narrowing-lock'), so that these hook
 functions cannot use `widen' to gain access to other portions of
 buffer text.
 

src/xdisp.c

@@ -36748,7 +36748,7 @@ Note that, when the buffer contains one or more lines whose length is
 above `long-line-threshold', these functions are called with the
 buffer narrowed to a small portion around POS (whose size is specified
 by `long-line-locked-narrowing-region-size'), and the narrowing is
-locked (see `narrow-to-region'), so that these functions cannot use
+locked (see `narrowing-lock'), so that these functions cannot use
 `widen' to gain access to other portions of buffer text.  */);
   Vfontification_functions = Qnil;
   Fmake_variable_buffer_local (Qfontification_functions);