include: don't rely on perl for printing prereq errors

Perl might not be present while checking prereqs, e.g. on a fresh
FreeBSD install.

Signed-off-by: Jo-Philipp Wich <jow@openwrt.org>

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@44276 3c298f89-4303-0410-b956-a3cf2f4a3e73

include/prereq.mk

@@ -35,7 +35,7 @@ define Require
 			echo 'ok.'; \
 		else \
 			echo 'failed.'; \
-			echo -e "$(PKG_NAME): $(strip $(2))" | perl -ne 's/\\\s*/\n/g,print' >> $(TMP_DIR)/.prereq-error; \
+			echo -e "$(PKG_NAME): $(strip $(2))" >> $(TMP_DIR)/.prereq-error; \
 		fi
 
     check-$(1): FORCE