fix(interdiff): move to fallback for the upstream completion

This moves the in-tree completion for interdiff to
completions-fallback.  The upstream patchutil-0.4.3 has started to
offer completion files as reported in Ref. [1].

[1] #1502

Author: akinomyoga

completions-core/Makefile.am

@@ -169,7 +169,6 @@ cross_platform = 2to3.bash \
 		inject.bash \
 		inotifywait.bash \
 		installpkg.bash \
-		interdiff.bash \
 		invoke-rc.d.bash \
 		ip.bash \
 		ipcalc.bash \

completions-fallback/Makefile.am

@@ -17,6 +17,7 @@ cross_platform = adb.bash \
 		hexdump.bash \
 		hwclock.bash \
 		insmod.bash \
+		interdiff.bash \
 		ionice.bash \
 		jj.bash \
 		jungle.bash \

completions-core/interdiff.bash completions-fallback/interdiff.bashcompletions-core/interdiff.bash renamed to completions-fallback/interdiff.bash

@@ -1,5 +1,8 @@
 # interdiff(1) completion                                  -*- shell-script -*-
 
+# Use of this file is deprecated.  Upstream completion is available in
+# patchutil >= 0.4.3, use that instead.
+
 _comp_cmd_interdiff()
 {
     local cur prev words cword was_split comp_args