patch 9.0.1221: code is indented more than necessary

Problem:    Code is indented more than necessary.
Solution:   Use an early return where it makes sense. (Yegappan Lakshmanan,
            closes #11833)
diff --git a/src/regexp_bt.c b/src/regexp_bt.c
index d2acbc2..33af278 100644
--- a/src/regexp_bt.c
+++ b/src/regexp_bt.c
@@ -3187,20 +3187,20 @@
     // When "rex.need_clear_subexpr" is set we don't need to save the values,
     // only remember that this flag needs to be set again when restoring.
     bp->save_need_clear_subexpr = rex.need_clear_subexpr;
-    if (!rex.need_clear_subexpr)
+    if (rex.need_clear_subexpr)
+	return;
+
+    for (i = 0; i < NSUBEXP; ++i)
     {
-	for (i = 0; i < NSUBEXP; ++i)
+	if (REG_MULTI)
 	{
-	    if (REG_MULTI)
-	    {
-		bp->save_start[i].se_u.pos = rex.reg_startpos[i];
-		bp->save_end[i].se_u.pos = rex.reg_endpos[i];
-	    }
-	    else
-	    {
-		bp->save_start[i].se_u.ptr = rex.reg_startp[i];
-		bp->save_end[i].se_u.ptr = rex.reg_endp[i];
-	    }
+	    bp->save_start[i].se_u.pos = rex.reg_startpos[i];
+	    bp->save_end[i].se_u.pos = rex.reg_endpos[i];
+	}
+	else
+	{
+	    bp->save_start[i].se_u.ptr = rex.reg_startp[i];
+	    bp->save_end[i].se_u.ptr = rex.reg_endp[i];
 	}
     }
 }
@@ -3215,20 +3215,20 @@
 
     // Only need to restore saved values when they are not to be cleared.
     rex.need_clear_subexpr = bp->save_need_clear_subexpr;
-    if (!rex.need_clear_subexpr)
+    if (rex.need_clear_subexpr)
+	return;
+
+    for (i = 0; i < NSUBEXP; ++i)
     {
-	for (i = 0; i < NSUBEXP; ++i)
+	if (REG_MULTI)
 	{
-	    if (REG_MULTI)
-	    {
-		rex.reg_startpos[i] = bp->save_start[i].se_u.pos;
-		rex.reg_endpos[i] = bp->save_end[i].se_u.pos;
-	    }
-	    else
-	    {
-		rex.reg_startp[i] = bp->save_start[i].se_u.ptr;
-		rex.reg_endp[i] = bp->save_end[i].se_u.ptr;
-	    }
+	    rex.reg_startpos[i] = bp->save_start[i].se_u.pos;
+	    rex.reg_endpos[i] = bp->save_end[i].se_u.pos;
+	}
+	else
+	{
+	    rex.reg_startp[i] = bp->save_start[i].se_u.ptr;
+	    rex.reg_endp[i] = bp->save_end[i].se_u.ptr;
 	}
     }
 }