buildPerlPackage: "properly" quote FULLPERL

pkgs/development/perl-modules/generic/builder.sh

···
         fi
     done
 
-    perl Makefile.PL PREFIX=$out INSTALLDIRS=site $makeMakerFlags PERL=$(type -P perl) FULLPERL=$perl/bin/perl
+    perl Makefile.PL PREFIX=$out INSTALLDIRS=site $makeMakerFlags PERL=$(type -P perl) FULLPERL=\"$perl/bin/perl\"
 }