OS X: Fixes check for OpenSSL version

We only care about Apple's OpenSSL when checking the version.  Any
other OpenSSL that happens to be in the PATH doesn't matter.

bin/ruby-build

@@ -714,7 +714,7 @@ use_homebrew_readline() {
 
 has_broken_mac_openssl() {
   [ "$(uname -s)" = "Darwin" ] &&
-  [[ "$(openssl version 2>/dev/null || true)" = "OpenSSL 0.9.8"?* ]] &&
+  [[ "$(/usr/bin/openssl version 2>/dev/null || true)" = "OpenSSL 0.9.8"?* ]] &&
   [[ "$RUBY_CONFIGURE_OPTS" != *--with-openssl-dir=* ]] &&
   ! use_homebrew_openssl
 }