.gitignore: ignore qmp-commands.txt

This file is moved out from QMP/ to BUILD dir, change the ignore file
too.

Signed-off-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Luiz Capitulino <lcapitulino@redhat.com>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
diff --git a/.gitignore b/.gitignore
index 8e1b73f..5584b5f 100644
--- a/.gitignore
+++ b/.gitignore
@@ -44,7 +44,7 @@
 qemu-bridge-helper
 qemu-monitor.texi
 vscclient
-QMP/qmp-commands.txt
+qmp-commands.txt
 test-bitops
 test-coroutine
 test-int128