mindtct: Check for multiplication overflow in alloc_power_stats()

Assert if any of the multiplications, which are then used to allocate
memory, would overflow.

Closes: #91
2 jobs from wip/hadess/nbis-mul-check in 2 minutes and 32 seconds
Status Job ID Name Coverage
  Build
failed #62503
build

00:02:32

 
  Test
skipped #62504
flatpak master
 
Name Stage Failure
failed
build Build
[19/93] Compiling C object 'libfprint/642ed89@@fprint@sha/drivers_aes1610.c.o'.
[20/93] Compiling C object 'libfprint/642ed89@@fprint@sha/drivers_aes2550.c.o'.
[21/93] Compiling C object 'libfprint/642ed89@@fprint@sha/drivers_aes2501.c.o'.
[22/93] Compiling C object 'libfprint/642ed89@@fprint@sha/drivers_upekts.c.o'.
[23/93] Compiling C object 'libfprint/642ed89@@fprint@sha/drivers_vfs101.c.o'.
[24/93] Compiling C object 'libfprint/642ed89@@fprint@sha/drivers_upeksonly.c.o'.
[25/93] Compiling C object 'libfprint/642ed89@@fprint@sha/drivers_uru4000.c.o'.
ninja: build stopped: subcommand failed.
ERROR: Job failed: exit code 1