disk: efi: buffer overflow in part_get_info_efi()

disk: efi: buffer overflow in part_get_info_efi()

In part_get_info_efi() we use the output of print_efiname() to set
info->name[]. The size of info->name is PART_NAME_LEN = 32 but
print_efiname() returns a string with a maximum length of
PARTNAME_SZ + 1 = 37.

Use snprintf() instead of sprintf() to avoid buffer overflow.

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>