Don't use $(EXHEADER) directly in for loops, as most shells will break
if $(EXHEADER) is empty.

Notified by many, solution suggested by Carson Gaspar <carson@taltos.org>

crypto/Makefile.ssl

diff --git a/crypto/Makefile.ssl b/crypto/Makefile.ssl
index e61a82a..c03bbc4 100644
--- a/crypto/Makefile.ssl
+++ b/crypto/Makefile.ssl
@@ -132,7 +132,7 @@
 	done;
 
 install:
-	@for i in $(EXHEADER) ;\
+	@headerlist="$(EXHEADER)"; for i in $$headerlist ;\
 	do \
 	(cp $$i $(INSTALL_PREFIX)$(INSTALLTOP)/include/openssl/$$i; \
 	chmod 644 $(INSTALL_PREFIX)$(INSTALLTOP)/include/openssl/$$i ); \