The libertine-legacy font has been replaced, try:
\fontfamily{LinuxLibertineO-LF}\fontsize{32}{32}\selectfont
Portability
If you want to make your code as portable as possible (Libertine has only been replaced recently, and has not been replaced for MiKTeX users) use:
\IfFileExists{libertine-type1.sty}{
\fontfamily{LinuxLibertineO-LF}\fontsize{32}{32}\selectfont
}{
\fontfamily{fxl}\fontsize{32}{32}\selectfont
}
This checks if the new libertine package is installed and defines your command based on that.
For old style figures, use LinuxLibertineO-OsF instead of LinuxLibertineO-LF.
Issues
If you don't use the libertine package, bold might not work.
To fix this, you either have to redefine \bfdefault:
\renewcommand*{\bfdefault}{b}
Or you'll have to change the way you use your quotes: don't use \bfseries or \textbf and define your font like this:
\fontfamily{fxl}\fontsize{32}{32}\fontseries{b}\selectfont
Letters available are m (medium) b (bold) and sb (semibold).
Example
\noindent
{\fontfamily{fxl}\fontsize{32}{32}\fontseries{m}\selectfont `'}
{\fontfamily{LinuxLibertineO-LF}\fontsize{32}{32}\fontseries{m}\selectfont `'}
{\fontfamily{LinuxLibertineO-LF}\fontsize{32}{32}\fontseries{sb}\selectfont `'}
{\fontfamily{LinuxLibertineO-LF}\fontsize{32}{32}\fontseries{b}\selectfont `'}
