patch 8.2.0967: unnecessary type casts for vim_strnsave()

Problem:    Unnecessary type casts for vim_strnsave().
Solution:   Remove the type casts.
diff --git a/src/terminal.c b/src/terminal.c
index 5514c73..5424574 100644
--- a/src/terminal.c
+++ b/src/terminal.c
@@ -3011,7 +3011,7 @@
     {
 	case VTERM_PROP_TITLE:
 	    strval = vim_strnsave((char_u *)value->string.str,
-						       (int)value->string.len);
+							    value->string.len);
 	    if (strval == NULL)
 		break;
 	    vim_free(term->tl_title);
@@ -3073,7 +3073,7 @@
 
 	case VTERM_PROP_CURSORCOLOR:
 	    strval = vim_strnsave((char_u *)value->string.str,
-						       (int)value->string.len);
+							    value->string.len);
 	    if (strval == NULL)
 		break;
 	    cursor_color_copy(&term->tl_cursor_color, strval);