overlay: Fix crash due to small debug buffer size

The debug buffer size is insufficient for newer targets with multiple
pipes. The code causing crash is enabled only if the PIPE_DEBUG macro
is enabled during local debugging.

We now increase the buffer size and also put some string operations under
the macro check for efficiency.

Change-Id: I4ad418d314fd8c7d374ccfdb0943dde44d968922
2 files changed