.gitignore: Ignore new autofoo tmp files

Change-Id: I155e9fd644263a8b47301f6b0986b9beb5a45d0f
diff --git a/.gitignore b/.gitignore
index 3d9c81b..fe53f71 100644
--- a/.gitignore
+++ b/.gitignore
@@ -26,6 +26,7 @@
 *.m4
 missing
 .deps
+*~
 
 *.pc
 .libs