patch 8.2.4750: small pieces of dead code

Problem:    Small pieces of dead code.
Solution:   Remove the dead code. (Goc Dundar, closes #10190) Rename the
            qftf_cb struct member to avoid confusion.
diff --git a/src/optionstr.c b/src/optionstr.c
index 2accd3d..3de23ba 100644
--- a/src/optionstr.c
+++ b/src/optionstr.c
@@ -1249,8 +1249,7 @@
 		int x2 = -1;
 		int x3 = -1;
 
-		if (*p != NUL)
-		    p += mb_ptr2len(p);
+		p += mb_ptr2len(p);
 		if (*p != NUL)
 		    x2 = *p++;
 		if (*p != NUL)