minor build fix in libssl

[YASUOKA Masahiko]

Hi,

Compiling sha256-x86_64.S fails if the "src" is located a directory
which includes "512".

The diff below fixes this problem.

ok?

Index: lib/libssl/src/crypto/sha/asm/sha512-x86_64.pl
===================================================================
RCS file: /cvs/src/lib/libssl/src/crypto/sha/asm/sha512-x86_64.pl,v
retrieving revision 1.2
diff -u -p -r1.2 sha512-x86_64.pl
--- lib/libssl/src/crypto/sha/asm/sha512-x86_64.pl      30 Apr 2014 13:40:02 
-0000      1.2
+++ lib/libssl/src/crypto/sha/asm/sha512-x86_64.pl      17 Dec 2015 02:58:51 
-0000
@@ -52,7 +52,7 @@ die "can't locate x86_64-xlate.pl";
 open OUT,"| \"$^X\" $xlate $flavour $output";
 *STDOUT=*OUT;
 
-if ($output =~ /512/) {
+if ($output =~ m#.*[\/\\][^\/\\]*512[^\/\\]*$#) {
        $func="sha512_block_data_order";
        $TABLE="K512";
        $SZ=8;