Remove "eng" macro

Never used.

Test: policy compiles.
Change-Id: I0ce6c46bb05925a4b3eda83531b28f873b0c9b99

public/te_macros

@@ -284,7 +284,6 @@ define(`recovery_only', ifelse(target_recovery, `true', $1, ))
 # SELinux rules which apply only to userdebug or eng builds
 #
 define(`userdebug_or_eng', ifelse(target_build_variant, `eng', $1, ifelse(target_build_variant, `userdebug', $1)))
-define(`eng', ifelse(target_build_variant, `eng', $1))
 
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 # SELinux rules for HALs that have either been binderized or are