[source] openssl: Use mkhash for STAMP_CONFIGURED

[LEDE Commits]

jow pushed a commit to source.git, branch lede-17.01:
https://git.lede-project.org/72fcdb6286ad7be24296acbd36043ee3e96e5ec4

commit 72fcdb6286ad7be24296acbd36043ee3e96e5ec4
Author: Florian Fainelli <f.fainelli at gmail.com>
AuthorDate: Wed Mar 1 10:48:32 2017 -0800

    openssl: Use mkhash for STAMP_CONFIGURED
    
    The current way of creating a STAMP_CONFIGURED filename for OpenSSL can
    lead to an extremely long filename that makes touch unable to create it,
    and fail the build.
    
    Use mkhash to produce a hash against OPENSSL_OPTIONS which creates a
    shortert stamp file,
    
    Fixes #572
    
    Signed-off-by: Florian Fainelli <f.fainelli at gmail.com>
---
 package/libs/openssl/Makefile | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/package/libs/openssl/Makefile b/package/libs/openssl/Makefile
index 9b64302..b39e3c6 100644
--- a/package/libs/openssl/Makefile
+++ b/package/libs/openssl/Makefile
@@ -168,7 +168,7 @@ else
   endif
 endif
 
-STAMP_CONFIGURED := $(STAMP_CONFIGURED)_$(subst $(space),_,$(OPENSSL_OPTIONS))
+STAMP_CONFIGURED := $(STAMP_CONFIGURED)_$(shell echo $(OPENSSL_OPTIONS) | mkhash md5)
 
 define Build/Configure
 	[ -f $(STAMP_CONFIGURED) ] || { \