Fix compiler warning
Fix compiler warning

pwent_mapper.c: In function 'pwent_mapper_find_user':
pwent_mapper.c:75: warning: 'str' is used uninitialized in this function


milgner/pam_pkcs11,milgner/pam_pkcs11,OpenSC/pam_pkcs11,milgner/pam_pkcs11,OpenSC/pam_pkcs11