Merge r1389077, r1456418, r1460399, r1460405:

r1389077:
easy fixes for a few warnings about unused variables

r1456418:
remove ignored rv

r1460399:
clean up a bit of error handling just to get rid of

  sockperf.c: In function 'main':
  sockperf.c:206:18: warning: variable 'rv' set but not used [-Wunused-but-set-variable]


r1460405:
hide an unused variable on Unix


All submitted by: trawick



git-svn-id: https://svn.apache.org/repos/asf/apr/apr/branches/1.4.x@1478929 13f79535-47bb-0310-9956-ffa450edef68