coverity#983173 Resource leak

Change-Id: I913ce32579ef9045fd3d33b48a653bc4ffc628da
Reviewed-on: https://gerrit.libreoffice.org/2206Tested-by: Caolán McNamara <caolanm@redhat.com>
Reviewed-by: Caolán McNamara <caolanm@redhat.com>

sdext/source/pdfimport/xpdfwrapper/pdfioutdev_gpl.cxx

@@ -451,10 +451,13 @@ void PDFOutDev::writeFontFile( GfxFont* gfxFont ) const
     fflush(stdout);
 
     if( fwrite(pBuf, sizeof(char), nSize, g_binary_out) != (size_t)nSize )
+    {
+        gfree(pBuf);
         exit(1); // error
-
+    }
     // ---sync point--- see SYNC STREAMS above
     fflush(g_binary_out);
+    gfree(pBuf);
 }
 
 void PDFOutDev::printPath( GfxPath* pPath ) const