core/bootloader.c: fix build without reallocarray
Created by: ffontaine
Use realloc instead of reallocarray to avoid the following build failure with uclibc raised since version 2022.05 and https://github.com/sbabic/swupdate/commit/b8897ed695e1cd954859142b14ec8546d2e7994a:
/nvmedata/autobuild/instance-0/output-1/host/lib/gcc/microblaze-buildroot-linux-uclibc/10.3.0/../../../../microblaze-buildroot-linux-uclibc/bin/ld: core/built-in.o: in function `register_bootloader':
(.text.register_bootloader+0x30): undefined reference to `reallocarray'Fixes:
Signed-off-by: Fabrice Fontaine fontaine.fabrice@gmail.com