Clang scan-build

Körde igenom fribid i clang scan-build (http://clang-analyzer.llvm.org/), och hittade två potentiella problem.

scan-build har ytterligare två till varningar, som jag inte riktigt greppat.
```
main.c:281:13: warning: Potential leak of memory pointed to by 'input.pkcs10'
            secmem_free_page(password);
            ^~~~~~~~~~~~~~~~

npobject.c:43:12: warning: Result of 'malloc' is converted to a pointer of type 'NPObject',
 which is incompatible with sizeof operand type 'PluginObject'
    return malloc(sizeof(PluginObject));
           ^~~~~~ ~~~~~~~~~~~~~~~~~~~~
```