patch 8.2.4043: using int for second argument of ga_init2()

Problem:    Using int for second argument of ga_init2().
Solution:   Remove unnessary type cast (int) when using sizeof().
diff --git a/src/strings.c b/src/strings.c
index 5c55c1e..f6affd6 100644
--- a/src/strings.c
+++ b/src/strings.c
@@ -893,7 +893,7 @@
     // set_vim_var_nr() doesn't set the type
     set_vim_var_type(VV_KEY, VAR_NUMBER);
 
-    ga_init2(&ga, (int)sizeof(char), 80);
+    ga_init2(&ga, sizeof(char), 80);
     for (p = str; *p != NUL; p += len)
     {
 	typval_T newtv;
@@ -1673,7 +1673,7 @@
     rettv->vval.v_string = NULL;
     if (fromstr == NULL || tostr == NULL)
 	    return;		// type error; errmsg already given
-    ga_init2(&ga, (int)sizeof(char), 80);
+    ga_init2(&ga, sizeof(char), 80);
 
     if (!has_mbyte)
 	// not multi-byte: fromstr and tostr must be the same length