Use %u in sprintf when printing unsigned integers

Use %u in sprintf when printing unsigned integers

This fixes the following messages of cppcheck:

[src/modules/rlm_eap/libeap/eapcrypto.c:108]: (warning) %d in format string (no. 1) requires 'int' but the argument type is 'unsigned int'.
[src/modules/rlm_eap/libeap/eapcrypto.c:119]: (warning) %d in format string (no. 1) requires 'int' but the argument type is 'unsigned int'.
[src/modules/rlm_eap/libeap/eapcrypto.c:126]: (warning) %d in format string (no. 1) requires 'int' but the argument type is 'unsigned int'.
[src/modules/rlm_eap/libeap/eapcrypto.c:133]: (warning) %d in format string (no. 1) requires 'int' but the argument type is 'unsigned int'.
[src/modules/rlm_detail/rlm_detail.c:236]: (warning) %d in format string (no. 1) requires 'int' but the argument type is 'unsigned int'.