perlPackages.BerkeleyDB: fix db dependency

This fixes a regression introduced in 4b06383.

[dezgeg squashed in to fit the changes introduced in "db: Use more
conventional outputs, also split bin"]

doc/languages-frameworks/perl.xml

@@ -109,8 +109,8 @@ buildPerlPackage rec {
   };
 
   preConfigure = ''
-    echo "LIB = ${db}/lib" > config.in
-    echo "INCLUDE = ${db}/include" >> config.in
+    echo "LIB = ${db.out}/lib" > config.in
+    echo "INCLUDE = ${db.dev}/include" >> config.in
   '';
 }
 </programlisting>

pkgs/development/perl-modules/BerkeleyDB/default.nix

@@ -9,7 +9,7 @@ buildPerlPackage rec {
   };
 
   preConfigure = ''
-    echo "LIB = ${db}/lib" > config.in
-    echo "INCLUDE = ${db}/include" >> config.in
+    echo "LIB = ${db.out}/lib" > config.in
+    echo "INCLUDE = ${db.dev}/include" >> config.in
   '';
 }