patch 9.0.1459: typo in name of type

Problem:    Typo in name of type.
Solution:   Change funccal_T to funccall_T. (closes #12265)
diff --git a/src/blob.c b/src/blob.c
index 6f42973..9b409f6 100644
--- a/src/blob.c
+++ b/src/blob.c
@@ -629,7 +629,7 @@
     if (b->bv_lock == 0)
 	b->bv_lock = VAR_LOCKED;
 
-    // Create one funccal_T for all eval_expr_typval() calls.
+    // Create one funccall_T for all eval_expr_typval() calls.
     fc = eval_expr_get_funccal(expr, &newtv);
 
     for (i = 0; i < b->bv_ga.ga_len; i++)