remove unused permissions scheme from amend

Amend (aka the recovery command language) had a half-implemented
scheme of limiting which commands OTA packages were allowed to
execute.  It's not clear what this was ever supposed to be good for.
Remove it.
diff --git a/amend/Android.mk b/amend/Android.mk
index ae2d44a..c3b7c32 100644
--- a/amend/Android.mk
+++ b/amend/Android.mk
@@ -10,13 +10,11 @@
 	ast.c \
 	symtab.c \
 	commands.c \
-	permissions.c \
 	execute.c
 
 amend_test_files := \
 	test_symtab.c \
-	test_commands.c \
-	test_permissions.c
+	test_commands.c
 
 # "-x c" forces the lex/yacc files to be compiled as c;
 # the build system otherwise forces them to be c++.