Merge tag 'kbuild-fixes-v5.17' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

Pull Kbuild fixes from Masahiro Yamada:

 - Bring include/uapi/linux/nfc.h into the UAPI compile-test coverage

 - Revert the workaround of CONFIG_CC_IMPLICIT_FALLTHROUGH

 - Fix build errors in certs/Makefile

* tag 'kbuild-fixes-v5.17' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
  certs: Fix build error when CONFIG_MODULE_SIG_KEY is empty
  certs: Fix build error when CONFIG_MODULE_SIG_KEY is PKCS#11 URI
  Revert "Makefile: Do not quote value for CONFIG_CC_IMPLICIT_FALLTHROUGH"
  usr/include/Makefile: add linux/nfc.h to the compile-test coverage
diff --git a/Makefile b/Makefile
index 3f07f0f..c94559a 100644
--- a/Makefile
+++ b/Makefile
@@ -778,7 +778,7 @@
 KBUILD_CFLAGS += $(stackp-flags-y)
 
 KBUILD_CFLAGS-$(CONFIG_WERROR) += -Werror
-KBUILD_CFLAGS += $(KBUILD_CFLAGS-y) $(CONFIG_CC_IMPLICIT_FALLTHROUGH:"%"=%)
+KBUILD_CFLAGS += $(KBUILD_CFLAGS-y) $(CONFIG_CC_IMPLICIT_FALLTHROUGH)
 
 ifdef CONFIG_CC_IS_CLANG
 KBUILD_CPPFLAGS += -Qunused-arguments
diff --git a/certs/Makefile b/certs/Makefile
index f7041c2..3ea7fe6 100644
--- a/certs/Makefile
+++ b/certs/Makefile
@@ -68,14 +68,14 @@
 endif # CONFIG_MODULE_SIG_KEY
 
 # If CONFIG_MODULE_SIG_KEY isn't a PKCS#11 URI, depend on it
-ifneq ($(filter-out pkcs11:%, %(CONFIG_MODULE_SIG_KEY)),)
+ifneq ($(filter-out pkcs11:%, $(CONFIG_MODULE_SIG_KEY)),)
 X509_DEP := $(CONFIG_MODULE_SIG_KEY)
 endif
 
 $(obj)/system_certificates.o: $(obj)/signing_key.x509
 
 $(obj)/signing_key.x509: $(X509_DEP) $(obj)/extract-cert FORCE
-	$(call if_changed,extract_certs,$(if $(X509_DEP),$<,$(CONFIG_MODULE_SIG_KEY)))
+	$(call if_changed,extract_certs,$(if $(CONFIG_MODULE_SIG_KEY),$(if $(X509_DEP),$<,$(CONFIG_MODULE_SIG_KEY)),""))
 endif # CONFIG_MODULE_SIG
 
 targets += signing_key.x509
diff --git a/usr/include/Makefile b/usr/include/Makefile
index 9440380..7be7468 100644
--- a/usr/include/Makefile
+++ b/usr/include/Makefile
@@ -34,7 +34,6 @@
 no-header-test += linux/ivtv.h
 no-header-test += linux/kexec.h
 no-header-test += linux/matroxfb.h
-no-header-test += linux/nfc.h
 no-header-test += linux/omap3isp.h
 no-header-test += linux/omapfb.h
 no-header-test += linux/patchkey.h