sys-libs/readline: Sync with Gentoo

It's from Gentoo commit 78213a89b4a602460bf81ba5fab8eed561091ade.

Author: Flatcar Buildbot

sdk_container/src/third_party/portage-stable/sys-libs/readline/readline-8.1_p2-r1.ebuild

@@ -3,7 +3,7 @@
 
 EAPI=7
 
-VERIFY_SIG_OPENPGP_KEY_PATH="${BROOT}"/usr/share/openpgp-keys/chetramey.asc
+VERIFY_SIG_OPENPGP_KEY_PATH=/usr/share/openpgp-keys/chetramey.asc
 inherit flag-o-matic multilib multilib-minimal preserve-libs toolchain-funcs usr-ldscript verify-sig
 
 # Official patches

sdk_container/src/third_party/portage-stable/sys-libs/readline/readline-8.2_p1.ebuild

@@ -7,7 +7,7 @@ EAPI=7
 # make anyway, so while this was added for RC versions, it's fine
 # in general.
 QA_PKGCONFIG_VERSION=$(ver_cut 1-2)
-VERIFY_SIG_OPENPGP_KEY_PATH="${BROOT}"/usr/share/openpgp-keys/chetramey.asc
+VERIFY_SIG_OPENPGP_KEY_PATH=/usr/share/openpgp-keys/chetramey.asc
 inherit flag-o-matic multilib multilib-minimal preserve-libs toolchain-funcs usr-ldscript verify-sig
 
 # Official patches

sdk_container/src/third_party/portage-stable/sys-libs/readline/readline-9999.ebuild

@@ -7,7 +7,7 @@ EAPI=7
 # make anyway, so while this was added for RC versions, it's fine
 # in general.
 QA_PKGCONFIG_VERSION=$(ver_cut 1-2)
-VERIFY_SIG_OPENPGP_KEY_PATH="${BROOT}"/usr/share/openpgp-keys/chetramey.asc
+VERIFY_SIG_OPENPGP_KEY_PATH=/usr/share/openpgp-keys/chetramey.asc
 inherit flag-o-matic multilib multilib-minimal preserve-libs toolchain-funcs usr-ldscript verify-sig
 
 # Official patches