Fixed a couple literals in alloc_mem routine.

...s to check wrong locations, or not realizing no memory is free. Also, added some indentation after some IF*s

Some of the ADD B, * were short by one, cause the routine to store numbers in wrong locations, and also to incorrectly try and allocate kernel space memory when userspace was full.

Slight correction. Just ensures the routine doesn't attempt to allocate kernelspace memory. The rest were fine.