Fix heap overflow in ARM.
Fix heap overflow in ARM.

In ARM the pointer returned by yr_notebook_alloc was being rounded up to a 4-bytes boundary, but the size of the buffer was not increased accordingly. This means the caller of yr_notebook_alloc could receive a buffer that is 1 to 3 bytes smaller than the requested sized.
hillu/yara,wxsBSD/yara,hillu/yara,wxsBSD/yara,wxsBSD/yara,hillu/yara,VirusTotal/yara,hillu/yara,VirusTotal/yara,VirusTotal/yara,hillu/yara,VirusTotal/yara,wxsBSD/yara,wxsBSD/yara,VirusTotal/yara