[Code Health] Delete spurious code

"num >= MAXADDRS" can never happen in the for-loop.

Test: 1. Modify system/etc/hosts to have over than MAXADDRS records, like
10.0.0.1    www.test.com
10.0.0.2    www.test.com
...
10.0.0.36   www.test.com
2. Trigger gethostbyname by "adb shell ping www.test.com"
3. Observe the result and there is no failure

Change-Id: I4347307be9479214c48492aee180d46e1b97d3f4