Enable -Wconversion: fold.c.

Refactor summary:
- foldinfo_T.fi_lnum: int --> linenr_T
                      Reorder field for optimal packing.
- foldAddMarker(..., markerlen): int --> size_t
    * foldstartmarkerlen: int --> size_t
        - foldDelMarker(..., markerlen): int --> size_t
            * foldendmarkerlen: int --> size_t

Helped-by: oni-link <knil.ino@gmail.com>

1 files changed, 1 insertions, 1 deletions

diff --git a/src/nvim/misc1.c b/src/nvim/misc1.c
index 5d8b88601e..e58ec71e77 100644
--- a/src/nvim/misc1.c
+++ b/src/nvim/misc1.c
@@ -796,7 +796,7 @@ open_line (
       ) {
     ++curwin->w_cursor.lnum;
     if (did_si) {
-      int sw = (int)get_sw_value(curbuf);
+      int sw = get_sw_value(curbuf);
 
       if (p_sr)
         newindent -= newindent % sw;