Avoid sed for dependency post-processing

It turns out that different sed implementations treat -i differently
to cause issues.  make it simpler by avoiding it entirely and give
perl the trust to be consistent enough.
Reviewed-by: NRich Salz <rsalz@openssl.org>

Configurations/unix-Makefile.tmpl

@@ -868,11 +868,6 @@ EOF
       }
   }
 
-  # The combination of perl and sed takes advantage of their respective
-  # capabilities.  Some sed implementations aren't greedy (enough), which
-  # is problematic with the some regexps.  However, the sed d command is
-  # simply easier in sed.
-  #
   # Should one wonder about the end of the Perl snippet, it's because this
   # second regexp eats up line endings as well, if the removed path is the
   # last in the line.  We may therefore need to put back a line ending.
@@ -894,8 +889,9 @@ $obj$depext: $deps
 	rm -f \$\@.tmp; touch \$\@.tmp
 	-\$(MAKEDEPEND) -f\$\@.tmp -o"|$obj$objext" -- \$(CFLAGS) $ecflags$incs -- $srcs \\
 	    2>/dev/null
-	perl -i -pe 's/^.*\\|//; s/ \\/(\\\\.|[^ ])*//; \$\$_.="\\n" unless /\\R\$\$/g' \$\@.tmp
-	sed -i -e '/: *\$\$/d' -e '/^\\(#.*\\| *\\)\$\$/d' \$\@.tmp
+	perl -i -pe 's/^.*\\|//; s/ \\/(\\\\.|[^ ])*//;               #\\
+	             \$\$_ = undef if (/: *\$\$/ || /^(#.*| *)\$\$/); #\\
+	             \$\$_.="\\n" unless !defined(\$\$_) or /\\R\$\$/g;' \$\@.tmp
 	\@if ! cmp \$\@.tmp \$\@ > /dev/null 2> /dev/null; then \\
 		mv \$\@.tmp \$\@; \\
 	else \\