milenage/aes: Address undefined behavior on bitshift

Extend the u8 to u32 before going to shift it.

Fixes:
milenage/aes-internal.c:799:4: runtime error: left shift of 128 by 24 places cannot be represented in type 'int'
    #0 0x7f84e9fe86a2 in rijndaelKeySetupEnc (/home/builder/jenkins/workspace/Osmocom_Sanitizer/source/libosmocore/src/gsm/.libs/libosmogsm.so.5+0xfa6a2)
    #1 0x7f84e9febad8 in aes_encrypt_init (/home/builder/jenkins/workspace/Osmocom_Sanitizer/source/libosmocore/src/gsm/.libs/libosmogsm.so.5+0xfdad8)
    #2 0x7f84e9fe7d14 in aes_128_encrypt_block (/home/builder/jenkins/workspace/Osmocom_Sanitizer/source/libosmocore/src/gsm/.libs/libosmogsm.so.5+0xf9d14)
    #3 0x7f84e9febe7d in milenage_f1 (/home/builder/jenkins/workspace/Osmocom_Sanitizer/source/libosmocore/src/gsm/.libs/libosmogsm.so.5+0xfde7d)
    #4 0x7f84e9fee2ce in milenage_generate (/home/builder/jenkins/workspace/Osmocom_Sanitizer/source/libosmocore/src/gsm/.libs/libosmogsm.so.5+0x1002ce)
    #5 0x7f84e9fe76d7 in milenage_gen_vec (/home/builder/jenkins/workspace/Osmocom_Sanitizer/source/libosmocore/src/gsm/.libs/libosmogsm.so.5+0xf96d7)
    #6 0x7f84e9fe6c08 in osmo_auth_gen_vec (/home/builder/jenkins/workspace/Osmocom_Sanitizer/source/libosmocore/src/gsm/.libs/libosmogsm.so.5+0xf8c08)
    #7 0x401441 in main (/home/builder/jenkins/workspace/Osmocom_Sanitizer/source/libosmocore/tests/auth/.libs/lt-milenage_test+0x401441)
    #8 0x7f84e8e33a3f in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x20a3f)
    #9 0x400e58 in _start (/home/builder/jenkins/workspace/Osmocom_Sanitizer/source/libosmocore/tests/auth/.libs/lt-milenage_test+0x400e58)

0 files changed, 0 insertions, 0 deletions