Simplify reading own process name

Bionic libc provides getprogname which 'returns the name of the program'
which is essentially what our custom readProcessName function does.

The notable difference is that it returns the full process name (not
only limited to 16 chars) as const char*, so adjust the code to work
with that.

Change-Id: I874911a82f6f784d8651d781083d2cc80ec840e1
1 file changed