define PURIFY for openssl for dbgutil to silence valgrind spew

Change-Id: I318ca368f26e42038a043b1e264a619795a9515e
Reviewed-on: https://gerrit.libreoffice.org/59945
Tested-by: Jenkins
Reviewed-by: Caolán McNamara <caolanm@redhat.com>
Tested-by: Caolán McNamara <caolanm@redhat.com>

external/openssl/ExternalProject_openssl.mk

@@ -82,6 +82,7 @@ $(call gb_ExternalProject_get_state_target,openssl,build):
 			$(if $(filter MACOSX,$(OS)),--prefix=/@.__________________________________________________OOO) \
 		&& $(MAKE) build_libs \
 			CC="$(CC) -fPIC \
+				$(if $(filter TRUE, $(ENABLE_DBGUTIL)), -DPURIFY,) \
 				$(if $(filter-out WNT MACOSX,$(OS)),-fvisibility=hidden)" \
 	)
 endif